Always take those articles with a grain or bag of salt, did you watch him play? 187 lbs my ass.
Farabee got knocked around on a regular basis and he's a lot tougher than Frost.
It takes time for undersized guys to develop strength and accept that they can't just skate around in the NHL.
The NHL has reverted back to a decade ago with this difference, instead of 220 lb slugs who can't skate, the league is full of 200 lb guys who fly (we have NAK, for example) and they do just as much damage to 175 lb guys along the boards.
Frost doesn't have to hit muscle beach, he just has to get strong enough to handle contact, and just as important, confident enough in his strength to venture into dirty areas, he's not going to make his living there, but he can't play as if he's allergic to contact.