I can understand your worry but through the first two weeks the texans showed their two extremes, running the ball and then throwing. Foster put up godly numbers the first week and still put up respectable numbers in week 2 when schaub threw for almost 500 yards. The texans will figure out a great mix between the two and foster will be a main ingredient.
Well Slaton has had some injury and fumbling problems and there is really not much to worry about.
I tell you what though, you might be sorry when Best runs away like Rice did last year...well anyone whose that big of a threat running and catching. See the thing is though, neither of these backs have lengthy resumes to bank on. and I don't think Megatron would appreciate that comment about Best being the only weapon. Pettigrew is pretty good young TE as well.