I agree that in bad weather you should try to run more, but the reality is that Cobb didn't do much with the ball on the occasions he did get it. Similarly, as TSN pointed out, Cobb didn't produce much against Edmonton until they let him break one outside on his big run to the one near the end of that game. Against a better defence like Sask, handing off with the likelihood of only a two yard gain and simply hoping the defence will blow their assignments and allow him to bounce outside for a big gain doesn't seem like sound strategy. Especially now that defences have started to develop a book on Cobb.
Besides, in weather like that, you expect the defence to key against the run since the weather hurts the passing game already. In those circumstances, you want a guy with size and power like Cates, Reynolds, or a healthy Lumsden to blast directly into the line with a decent chance for 6+ yard gains. Much has also been made already of the gimmicky things Sask's front seven do that make life difficult for the O-line. Again, you're better off in that situation if you have the type of back who hits the hole fast but can still muscle his way through a crowd. None of our three top backs bring that type of play to the table.