for wonderful example of what not to do[as in crappling] please search function "multiphasic"
Yeah those Eddie Bravo-Bruce Lee nutriders are...yeah...
Position, position, position, position. If you're having problems sinking in the subs, then chances are that your position is slightly off. If you can get total positional dominance, you can take your pick of even the most simple subs to apply. Try positional rolling with some of your partners, with no subs.
And it's not always that you are plateauing. It may be that your rolling partners are just getting better and catching on to things that you used to catch them with. Which takes us back to positional dominance. If you can positionally dominate, there's not a hell of a lot that they can do.