i would say so..those plants look huge! usually you wanna start scrog around the 5th node, maybe when theyre like 3-4 weeks old. you could try to tie the tallest ones down, it looks like theyre getting decent light though. GL
ya dude.. you need to start scrogging at the latest when you go into flower from veg.. otherwise you kinda affect the flower... but you could easily just snap some of those colas over to bring the light down the the lower plant a bit..