For a modest size trawler, I think that getting all tanks of fluids to the boat's CG would be better. So if pushing the engines back (behind the cabin) with a V-Drive will help that, it sounds good.
Also, if the V-Drive is separate from the engine mount (bell housing) so that the engine can be rotated, I think it would be very beneficial to put the drives closer to the center of the boat, so the props have better protection (ideally with a keel between to separate fluid flow) and tilt the drives outward, so that the input shaft is at an angle (viewed from the top) while the output shafts are parallel to the keel (again, viewed from the top). Such a tilt will move the engines further apart than the props, facilitating room for servicing. There is no negative impact on propulsion, because the prop doesn't know (or care) what's at the other end of the shaft.
If you combine this with a tunnel for the props, the tilt will place the engines beside (and higher than) the props in the tunnel, lowering the weight, and also lowering the floor-height above the engines.
Again, I'm not talking about laying the V-Drives on their sides. Just tilting them maybe 20 to 30 degrees off vertical, away from the center of the boat, to swing the engines out and away from each other, while moving the props closer to the center.
Have you seen this done?