Donno without the context. The guy who has just showed up is the toughest in the business. Or the product they are introducing is the toughest made so far.

eliot is as weak as they come :D

Usually it means "toughest" (i.e., the most tough thing/person). So, "That guy is as tough as they come" means he is a very, very tough man.

So they gotta be some allegedly tough guys huh?