Highly doubtful, if not completely preposterous.
- illegal (unless they wanted to face a two-side war against the Romulans as well)
- 100 years out of date (also hugely flawed at its conception)
- ??? (they had phasers and they had deflector shields but never heard of this technobabble before)
Fleets of Defiants
- They went into mass production during the war anyway
Federation Orbital Defence Platforms
- These would be satellites for the defence
of planets from orbit
, not much use when fighting sectors away from UFP worlds in open space
Tactical and Command EMHs
- Holograms are only as good as they are programmed, they don't have the experience, imagination or good-old gut feelings the sentient being do. Not to mention the memory and processing power the ships computer would need, the energy drain it would lead to, the possibility of system corruption or hacking, or the whole thing just breaking down. They are tools to be used in emergencies, not to be relied on to crew ships (also the UFP has 150+ member worlds, Starfleeters aren't all human). Seeing as how the Mark-1 was considered a failure and put to mining, why not wipe its "personality" and reprogram it to go and build ships, putting proper crews where they belong.
Starfleet has a military structure and is responsible for the defence of the Federation against aggressors, but that is only part of what it does. Having them geared up for war all the time flies in the face of there mandate to explore space, seek out new races, and the general optimism for all our future holds that Star Trek is about.
When the war started, Starfleet did throw everything they had at it, but still wasn't enough in the face of an enemy that had a tactical advantage, seemed capable of building ships quickly, could grow new troops in days, and had a race capable of infiltrating Starfleet and the UFP at any level to spy on them and destabilise their entire wartime operations.
Besides, when fighting a war, leaders want to put themselves into as good a position as possible to ensure victory--which is why governments make treaties and defence pacts in the first place. The UFP/Klingon alliance makes huge sense, and when Sisko does whatever he needs to in order to bring the Romulans into the fight as well it puts them in a better position yet again.