What’s unclear with Dooku are his motivations. He reveals Sidious’s plot to Kenobi, but then we learn he’s actually working for Sidious, so why did he reveal the plan? For the majority of AOTC we are lead to believe that he is seeking civil war against the Republic (for independence I guess? Unclear the Separatist motivations), and then we find out he’s enacting out Sidious’s orders. So we are I guess left to believe it’s just galaxy domination/Sith at last getting revenge? Which is fine, but it’s messy and muddled for him.
For Snoke, first of all he’s not the primary villain of either film he’s in, second, his plan is clear from the start - eliminate the Jedi and destroy the Republic.