In one of my teams i always played with 3 DC since day one and they are already in there 8th season.

Never won any title but i normaly fight for top 4 in LEAGUE, 2 CL FINALS AND 1CUP

For my 8 seasons experience, for the 3 defender tactic to work you need to have a strong midfield.
3 defenders wide i dont have experience but for what i have seen, can work good with1 or 2 DMCs.