Like in the settings somewhere or a toggle? so that i don't have to scroll down as much to check the game forums?

It's not possible, no.

But I'd recommend bookmarking games that you visit frequently so that you don't have to scroll down to find the forums for a game. It'll make accessing them much easier and quicker.

Should move the marathons to the bottom then.

if you aren't following ANY games, the site will show the entire game list. So moving the marathons to the bottom wouldn't be a smart move in terms of visibility for users who aren't following any games.