Usually from an engineering / cost perspective, it would rarely be done in the real world, for the same reasons why real-world battleships can't go very fast using their propellers in reverse (it does "work", but not well).
That point is a rather bad comparison, since real-world battleships have an entirely method of propulsion. I think the best comparison should be in current space craft (obviously). How many rockets have you seen that can reverse the direction of its thrust? That's the main issue here
Again, rocket is still not the best comparison. In fact there's no known good comparison i guess.
Current spacecraft are most orbiting in nature, their movement simply involve adjusting the orbit, be it the orbiting height, the change of orbiting pivot from earth to moon, or to use gravitational acceleration (sorry my bad english for special terms, but still should get the meaning i hope) to get to the needed escape velocity....
and for that, speed is almost the only thing current spacecraft got to control, hence it's only need/capable of speed up and slow down for such adjustment , hence forward thrust is never there nor the tech level allow
but in star sector/more ideal spacecraft environment, i still tend to believe forward thrust, need not to be a conventional main engine, can be a charged emergency engine thats compact but high power which can't last long, etc, is somewhat essential.
hope i din't make it too board sense, but a forward mounted engine thats more powerful than the lateral engine is needed in my imagination(and only in mine for now it seems)
having it allow battleship to
1)arrive tactical destination earlier without the need to slow down much earlier for the lack of stoping power, or turning 180' which is not always feasible, and mostly not feasible in battlefield when you got the shield strength, ship weakspot, weapon coverage to keep in mind
2)higher maneuverability obviously, say in asteroid belts. You don't fly in opposite direction, but even if you follow the flow their speeds aren't exactly consisten
3)reliability. while you can very reasonably see that the forward engine could be another giant weakspot, it can however, also see as a backup engine that offer additional mean to control the ship (assuming not conflicting with my earlier suggestion of using short burst engine)
not trying to state i am correct, just want to test are my reasons at least able to stand for a while if i put a forward engine to my current WIP ship which is about 2 km large.