Hi, Takata
Overall, this is not very surprising that the engines are lying at the edge of the debris field (excepted one large piece) considering it is presumed that they were the first to hit the surface.
Still supposing they hit surface first:
1) When they separate from a/c IMO they would travel further than other a/c pieces. Reasons:
a) A/c horizontal speed
b) itīs inertia (mass)
c) Less "water braking capability" (better hydrodynamics)
Hence it seems to me that they are in the "end" of the debris field farther from the point a/c hit surface.
* And no 'important" local submarine currents, what is probable due the debris concentration.
PS
My objective now is to have some insight on the trajectory of a/c at the end of itīs "flight" from FL350. I am anxious to learn at least how far the debris field is from LKP. I understood they did not revealed yet the recovery ship position.
Who knows itīs PSN?