First off I don't wanna hear what if this guy did this and this guy didnt cramp up. Whatever, fact is Sell beat them on that day. He ran within himself and didn't try to run over his head early in the race.
But if you wanna say what if. What if all those guys didnt drop out or weren't hurt. Who's to say they couldn't run with Hall. What if Meb and Abdi and KK were top 3. Personally if KK caught that group of 5 when he was running alone I think he would have put the fear of God in them, and judging by Hall's comments he was a bit concerned when he made his move.
But, thats what is great about sports, you can debate the whatifs (I know I've done it in other sports when my team losses), but it won't change anything and i think discussing what might of happened is an insult to 3 guys that ran great races and made the team.