Actually 2-D representation is not that bad, because the problem is axially symmetric, and actually 1-D at great distances as being both in their own star systems there are not that many meaningful trajectories they can take to meet in some volume in the galaxy to start the engagement.
You can take look a the game "Children of a Dead Earth" which tries to simulate combat in space. Scott Manly did some gameplays, and you can get an impression what is happening there by watching those videos.
What is interesting is evolutions of strategies in the game itself, as I heard from people who played it, because of changes in tech or physics.(do not know how big those changes were, I guess not that big, as the game tried to be simulator from the start). And that kinda proves for me that tactics are sensitive to small changes in tech and environment.
Again the tech used in the game is good enough for combats across all the stellar system, so it does not have to be around planets. The tech has good delta-v around 100-200 km/s, is capable of staging so for some projectiles it can be even more. But I heard most of the people do orbital combats. I guess that is the result of troubles manage particular types of actions because you have to make to many maneuvers by yourself without combat computer assistance, and that makes certain tactics hard to implement, and that could be translated to your question as for how advanced are technologies supporting the combat mechanics in you possible setting.
Would be a programming of guidance systems and tech be possible in the game, including orbit planning and maneuvering - it would open in the game different tactics which would nullify previous tactics, and use the full potential of current tech. The same had a place in the real world in different times last 300 years, especially in the least 100+ years. Same will be in the future.
So you have not enough information to answer your own question because answering is sensitive to details of available tech. The FTL alone is the cat in the bag and what it may bring to the table is not clear at all.
Notes about the setting
The ships used in combat are mainly fielded by major empires, and consist of heavily armed capital ships, lighter but faster escorts, and fighters for close combat.
- dump fighters, it is a common trope and it is flawed as a rotten apple.
- Mass and accelerations - bigger mass does not mean lower acceleration or less delta-v, it easy can be opposite to that. In general acceleration rates are similar. As an example, 1m sphere, with engine and shell of 1mm tick, being scaled to the 1km sphere and the shell with thickness 31'600mm will be the same percentage of mass for the bigger ship as it was for small one with 1mm thick shell. And they can have the same acceleration rates with no problems.
- you do not have to be a big empire to build a big ship, you just have to have the technology and a place where to build it freely.(a star system). Steal the technology, buy the technology or actually develop it. Ships are built not with humans labor - welders or who else, but by machines.
Weapons in use are railguns/coilguns, antimatter missiles, self-propelled kinetic impactors
- stick to missiles, they seem to be a good deal
Ships have hundreds to thousands of airtight bulkheads to survive breaches and electromagnetic shields as rudimentary protection
- airtight bulkheads - you do not need that, use space suits, the rest the equipment have to be capable of working in the vacuum.
Just stick to some game you like the most, they are simulators of possible combats with technologies given by the game rules. And by their own rules, they are pretty accurate about possible tactics. Eve online, children of death earth - are pretty ok. They have their own flaws which do make them not valid as a representation of possible reality in general, but they contain elements which could be valid at certain epochs of developing the space combat.