Various scriptures such as the Mahabharata have prescribed a maximum of three wives for Kshatriya men:
"Bhishma said, 'For the Kshatriya, O delighter of the Kurus, two wives have been ordained. The Kshatriya may take a third wife from the Sudra order. (Mahabharata, Anushashana Parva, Section XLVII)
Now, Shree Krishna, despite being a Kshatriya, had a total of 16108 wives:
The holy and illustrious Ananta (who had taken birth as Balarama) proceeded to the region below the Earth. Through the command of the Grandsire, he, aided by his Yoga power, supported the Earth. Vasudeva was a portion of that eternal god of gods called Narayana. Accordingly, he entered into Narayana. 16,000 women had been married to Vasudeva as his wives. When the time came, O Janamejaya, they, plunged into the Sarasvati. Casting off their (human) bodies there, they re-ascended to Heaven. Transformed into Apsaras, they approached the presence of Vasudeva. (Mahabharata, Svargarohanika Parva, Section V)
So why did He exceed the number of wives as prescribed by the Smriti?