Totally agree. I like some aspects of the Dominion war, there were some great episodes but a lot of dumb ones too, something that perhaps a separate topic might get into in greater detail.
But I completely agree that no one really sat down and asked "What is the military power potential of the Federation?" "what would their battle plan be?" Now to be fair to the writers the Federation seemed to go to war half assed in the past and perhaps this "we will get their eventually" plan just was not enough against the Dominion. But then again they seemed to rebuild pretty fast after the Borg attack and it seemed that they learned from the Borg invasion and should have been better prepared.
The one good thing "Q" did for the UFP was wake them to the threat of the Borg. When the Borg first came and whooped the UFP at Wolf 359, they effectively forced the Federation and Starfleet to be ready. This made them ready for the Dominion War IMO. Since they were in a massive preperation phase against the Borg, they didn't get caught with their pants down when the Dominion war started.
After the Dominion war, they should now get it through the Federations head, not everybody will play nice and negotiate. You need to have a massive fleet, weapons that are so deadly, that nobody will think of pushing you around. Don't get me wrong, I'm the farthest thing from a war monger. But I also don't like being bullied, I also don't like others bullying the weak. Ergo strength should be used for protection and preventing conflicts. Fighting only if you have to and killing as a absolute last option.
That's the problem when you plan things season by season without any fore thought into the universe you're trying to build.
JMS is still IMO one of the greatest Sci-Fi creators because of Babylon 5. He planned it from start to finish. A 5 year run that was largely in tact. There were details he didn't fore see like how fast is hyper-space. His answer was "The speed of plot". I'm not down with that. I'd prefer a "24" mentality where things were approached with a serious more realistic attitude towards travel time. At least for most of the early seasons that rule was followed.
Sadly when Branon Braga took over for one of the later seasons of "24", he threw that rule to the curbside. Another reason why BB should be booted from Hollywood. His lack of respect for continuity or what a show establishes.
Star Trek has one of the largest and richest Universe when it comes to canon material. We have 5 TV series and so many movies.
Star Wars has what, 6 movies, and some semi canon other stuff.
Given how big Star Trek is, how long it's run, I'm surprised it's as coherent as it is with not that many self contradictions.
The main problem lies with the writing staff and not having somebody who is a true knowledgebase of all things Trek and to help keep things consistant.
Especially the usage of terminology.
If there were to ever be a new show, they need somebody to keep the writing staff in line and make sure they have a consistant, logical universe. One that doesn't introduce new contradictions. One that follows logical rules and doesn't do things because it looks good now, but people will find it stupid later on (e.g. During most of the fleet battles in DS9, you never saw shields, this was a artistic decision by the directors, that's incredibly dumb and breaks the logic of the Star Trek Universe).