I made different other runs to test shortcuts for achieving 100% completion and noticed something strange. On PC, it's impossible to skip the tutorial and the first fight in Venice to reach 100% (you'll be stuck at 98%). However, on Switch, it's perfectly possible (and there are probably other possible shortcuts).
So, the Switch version is completely broken as you can skip parts of the game while on PC no. We maybe need to update the rules to separate PC and Switch (and maybe other plateforms) or to make the only valids wins conditions "finish the game and collect all diamond helmets, find all postcards, beat all challenges" like what we have now (except you don't have to see 100% completion on Progression tab).
(sorry if I'm not clear, I'm non native english. Do not hesitate to ask me to rephrase

)