Option A: If he frontruns the whole thing he won't be able to go faster than 3:27 high - 3:28 low. This is well within Kerr's PB range particularly when he gets to draft off Jakob for the whole race.
Option B: if he sits back and tries to surge from ~600m out he'll still get outkicked by Kerr because he won't have damaged him as much as in the first option. Kerr won't be stupid enough to frontrun in this case, he'll have a similar plan.
Option C: if it's a slow race then it's suicide as it opens the door to the really fast kickers like Hocker.
Seems to me like he needs to bait Kerr into sharing the lead while also keeping the pace fast enough to stop the field from enrering the conversation. Either that or frontrun a 3:26 Rudisha 2012 style, but that is way harder to do in the 1500.