...Also, Starfleet probably needs tugs that can tow starship wrecks that are not nice and intact Galaxy
saucers but are at least as massive. Say, a badly damaged whole
starship of that class.
can no doubt tow another Galaxy
, and perhaps dozens if need be. But we have already seen that a relatively small tug can pull a load ten times its size at least (DS9 "Time to Stand"). Starfleet's easiest choice for recovering a Galaxy
saucer would then be the same as with every other towing job: to use these already existing small tugs in sufficient quantity.
No doubt there are advantages to a single large tug in some circumstances, and no doubt Galaxies
can swap saucers in emergencies (even though no two halves might be perfectly compatible unless they had already spent months together getting properly acquainted). However, battlefield and post-battlefield logistics might best rely on the flexible use of smallish tugs.