^The question is not whether the Federation could have used drone ships against the Dominion but whether they would be able to keep up with the Dominion's numbers. Holograms require sophisticated programing, especially those expected to perform bridge operations on a starship. Serving as captain of a vessel isn't the same thing as maintaining a waste extraction system.
A stalemate isn't reached due to a lack of change in numbers. Stalemates occur when neither side is able to gain a tactical advantage over the other. Manpower may help tip the balance, but it matters less than the use of effective strategy and decision-making.