All these teams signing a RB does not exclude them from taking BPA. Well just Arizona if they get Edge,. All these RB's could end up in RBBC though and draft value would be hurt. I just think Alexander, McAllister, Johnson and McGahee being drafted despite no need for RB.
The only one of those examples that really fits here is McAllister, and even he was in a situation where the team was starting to realize that their starting RB was kind of well....crazy.As for the others...
Alexander and Johnson were drafted behind 30+ RBs (and in KC's case also a RB with no contract who they couldn't come to an agreement with). Their situations are comparable to the Jets and Patriots situation in this year's draft, both of which are teams I including on my list of possible destinations.
Likewise, Mcgahee was a special case in that he was seen as a special talent who dropped because of injury to a point where a team could use a late pick to get a guy with the talent to be a top 3 pick. There is no one comparable this year, though the "special talent" case where a guy could go to a team that has no need there falls right in line with listing Houston on my list for Bush, despite them having no need at RB.
I certainly agree with you that there are examples (like McAllister) of teams picking a guy in an area that they don't need, but likewise there are even more examples of guys with the talent to go fairly early falling much later because there is no need there. We saw it last year with Rodgers, we saw it the year before with Steven Jackson, and it's certainly not out of the question for it to happen again this year with a guy like Maroney, White, or possibly an outside shot of even Williams.
It's also reasonable to assume that the RB may not have to fall all the way down to 30 for Indy to nab them, as we've seen several instances where a guy falls far enough that he doesn't fall to a team, but close enough to a team where he was then in a spot that they could afford to trade up to (Jackson and the Rams, K. Jones and the Lions are examples of this).
Remember we've heard reports of how many GMs feel that this year's draft is set up such that after the top 15 or so, the next 40 prospects grade out very evenly and as such many teams in the 15-25 range will be looking to trade down. It's not unreasonable to assume that Indy could possibly trade up to that area if one of those guys that they really like is available there and they were unable to bring anyone in via FA (of course assuming Edge is gone as well).