I agree that Biseswar is more useful in the center. In fact I wouldn't mind seeing them flip positions in the above lineup. Pelkas does not have as much of a drop off when playing on the wing. He's definitely better at driving in as a striker than Biseswar, though.
Why not use them both in a 4-4-2 diamond, I say!
--Esiti--
--Jaba-- --Stoch--
--Biseswar--
--Pelkas--Akpom--
Unf that's a lot of firepower