Cover up your lack of knowledge anyway you want. Robinson not being as good as Tolbert (in your opinion) does not make him not a legit FB. No body said Lynch or Gore were not legit. You said a guy who made the pro-bowl was not legit.
On a side note, Tolbert was not coming here! He has said he would like to go to a team were he has a chance to be used more as a RB than a FB. I also agree you don't watch much football if you would rather have Jacobs back there, for such a big back he tries to avoid more contact than most QBs.