Here are 2 guys pretty much the same rating and one averages 1.5 fpg and the other 2.8 fpg. Can anyone explain.
http://www.whatifsports.com/hd/PlayerProfile/Ratings.aspx?tid=0&pid=2862014 Johnson avg. 2.8
http://www.whatifsports.com/hd/PlayerProfile/Ratings.aspx?tid=3292&pid=2820037 Bautista avg 1.5

The 6 points in speed and 1/3 (or more) in IQ probably are the biggest factors.

Hmm intersting. Didn't think 6 points and B+ to a A- would be that big of a deal. Thanks Trenton

I'll also toss out that the position you have them playing at is contributing to the difference -- the PG and SG slots tend to be more foul-prone in my experience under the Sim, so the fact the 2.8 guy is starting at point and the 1.5 guy appears to be your starting SF in the box scores I looked at is also a part of the disparity. 

Of course the caveat here is I haven't read your box scores enough to pay attention to substitution patterns, so I'm assuming that the starting position is where each player is getting the bulk of their game minutes. 

Don't overlook elite stamina vs average stamina

Is the 2.8 guy dippning into orange frequently?

It's probably a combonation of all these factors......the 1.5 guy is a little better in a lot of things.....

Ok. I checked 5 plp and 2.8 guy is not ever in orange. Both guys are starters and don't sub in at any other position. Yes the 1.5 is a little better in most important categories. Why is pg position more prone to foul trouble in fcp? Is it because he is at the point if the press and is first person to come into contact with the other team? Or is it because when intentionally fouling he automatically gets the fouls at pg?

Check the pbp of the games where the 2.8 fouled out or picked up 4 fouls......was he  covering someone vastly better than him?