lets consider some points
sivasya sri visnorya iha guna-namadi sakalam
dhiya bhinnam pasyet sa khalu harinama-hitakarah
It an offence to consider the names of demigods like Lord Siva or Lord Brahma to be equal to, or independent of, the name of Lord Krsna.
(Padma Purana, Brahma-Khanda, 25.15-18, 22-23)
So although Siva and Krishna are one Person but they have differnt Positions
Siva is therefore listed as a Mahajana and the greatest Vaisnava-
svayambhur naradah sambhuh
kumarah kapilo manuh
prahlado janako bhismo
balir vaiyasakir vayam
"These are twelve great authorities in preaching God consciousness. The name Sambhu means Lord Siva. His disciplic succession is also known as the Visnusvami-sampradaya, and the current Visnusvami-sampradaya is also known as the Vallabha-sampradaya. The current Brahma-sampradaya is known as the Madhva-Gaudiya-sampradaya. Even though Lord Siva appeared to preach Mayavada philosophy, at the end of his pastime in the form of Sankaracarya, he preached the Vaisnava philosophy: bhaja govindam bhaja govindam bhaja govindam mudha-mate. He stressed worshiping Lord Krsna, or Govinda, three times in this verse and especially warned his followers that they could not possibly achieve deliverance, or mukti, simply by word jugglery and grammatical puzzles. If one is actually serious to attain mukti, he must worship Lord Krsna. That is Sripada Sankaracarya's last instruction."
also
Adi Guru Sri Brahma has stated -
ksiram yatha dadhi vikara-visesa-yogat
sanjayate na hi tatah prthag asti hetoh
yah sambhutam api tatha samupaiti karyad
govindam adi-purusam tam aham bhajami
TRANSLATION
Just as milk is transformed into curd by the action of acids, but yet the effect curd is neither same as, nor different from, its cause, viz., milk, so I adore the primeval Lord Govinda of whom the state of Sambhu is a transformation for the performance of the work of destruction.
(The real nature of Sambhu, the presiding deity of Mahesa-dhama, is described.) Sambhu is not a second Godhead other than Krsna. Those, who entertain such discriminating sentiment, commit a great offense against the Supreme Lord. The supremacy of Sambhu is subservient to that of Govinda; hence they are not really different from each other. The nondistinction is established by the fact that just as milk treated with acid turns into curd so Godhead becomes a subservient when He Himself attains a distinct personality by the addition of a particular element of adulteration. This personality has no independent initiative. The said adulterating principle is constituted of a combination of the stupefying quality of the deluding energy, the quality of nonplenitude of the marginal potency and a slight degree of the ecstatic-***-cognitive principle of the plenary spiritual potency. This specifically adulterated reflection of the principle of the subjective portion of the Divinity is Sadasiva, in the form of the effulgent masculine-symbol-god Sambhu from whom Rudradeva is manifested. In the work of mundane creation as the material cause, in the work of preservation by the destruction of sundry asuras and in the work of destruction to conduct the whole operation, Govinda manifests Himself as guna-avatara in the form of Sambhu who is the separated portion of Govinda imbued with the principle of His subjective plenary portion. The personality of the destructive principle in the form of time has been identified with that of Sambhu by scriptural evidences that have been adduced in the commentary. The purport of the Bhagavata slokas, viz., vaisnavanam yatha sambhuh, etc., is that Sambhu, in pursuance of the will of Govinda, works in union with his consort Durgadevi by his own time energy. He teaches pious duties (dharma) as stepping-stones to the attainment of spiritual service in the various tantra-sastras, etc., suitable for jivas in different grades of the conditional existence. In obedience to the will of Govinda, Sambhu maintains and fosters the religion of pure devotion by preaching the cult of illusionism (Mayavada) and the speculative agama-sastras. The fifty attributes of individual souls are manifest in a far vaster measure in Sambhu and five additional attributes not attainable by jivas are also partly found in him. So Sambhu cannot be called a jiva. He is the lord of jiva but yet partakes of the nature of a separated portion of Govinda.
NOW WHY DID SAKARACARYA PREACH MAYAVAD?
sankarah sankarah saksat: ’Sankaracarya is none other than Mahadeva-Sankara, or Sivaji.’ You should always remember this. Sankara is guru for the Vaisnavas, and for this reason Mahaprabhu has referred to him as acarya (spiritual preceptor). For his own part, Sri Sankara was a perfect Vaisnava. “At the time Sri Sankara’s appeared in India, there was a great need for a guna-avatara like him, an incarnation who presides over the qualities of material nature. The study of the Vedic sastras and the practice of varnasrama-dharma had become practically extinct in India due to the influence of sunyavada (voidism), the nihilistic Buddhist philosophy. Sunyavada is vehemently opposed to the personal conception of Bhagavan. Although it partially accepts the principle of the living being’s identity as a conscious, spiritual soul (jivatma), it is an extreme example of anitya-dharma (impermanent religion). The brahmanas of that era had abandoned the Vedic dharma and had in effect all become Buddhists. At that point, Sankaracarya appeared as an extremely powerful incarnation of Mahadeva. He re-established the credibility of the Vedic literatures and converted the sunyavada doctrine of voidism into the brahmavada doctrine of nirvisesa (featureless) brahma. This was an extraordinary feat, and India will remain ever indebted to Sri Sankaracarya for this tremendous contribution.
“All activities in this world fall into one of two categories: some are relative to a particular period of time, and some are applicable for all time. The work of Sankaracarya was relative to a particular period and bestowed tremendous benefit. Sankaracarya laid the foundation upon which great acaryas such as Sri Ramanujacarya erected the edifice of pure vaisnava-dharma. Consequently, Sankaravatara was a great friend and preceptor who pioneered vaisnava-dharma. “Vaisnavas are now reaping the fruit of Sankaracarya’s philosophical precepts. For the jivas who are bound by matter, there is a great need for sambandha-jnana, knowledge of the soul’s entanglement in material nature and of his relationship with Bhagavan. Sankaracarya and the Vaisnavas both accept that the sentient living entities in this material world are completely distinct and separate from their gross and subtle material bodies, that the jivas are spiritually existent, and that liberation (mukti) entails giving up all connection with this material world. Consequently, there is a great deal of agreement between the doctrine of Sankara and that of the Vaisnava acaryas, up to the point of liberation. Sankara has even taught that the worship of Sri Hari is the method by which one can purify the heart and attain liberation. He has only remained silent regarding what extraordinary destination the jiva attains after liberation.