It depends of course on your players. If you have players that love stat management, just add some and then some.
Generally, just add to the game what you feel is fun for your group.
My statement from above was probably a little bit too me-centric.

I already felt it was too much when playing zombicide.

that's a game you play three or four times in total if you have a time budget as limited as mine, and for three or four games only, that list of specials was already annoying.
Of course if you play that same game passionate and often, so maybe a total of 20 or 30 times, or if you play it with a table full of passionate rpg players, then the zombicide list of specials is too small.
I love Heroquest here because all the specials are written out on game cards. You have a huge list of specials if you count. Around 300. But as you see only the few that are currently being used, the learning curve remains relatively flat.