My suggestion is for a new faction to be added to a few of the conquest missions only the ones that use all 5 eras. This faction Is only available for the player to play and will not show up naturally if you play any other faction essentially being a player unique faction that lets players do things their own way. This faction will also only start with 2 planets, one with a tier 3 starport and one with a tier one or two this is to make the game much harder for this faction in the early game due to its unique feature, which is they can build any ship that is available to any faction at the current tech tier based on what planets they control (unique variants excluded example: Crimson Victories) as an example controlling republic planets gives republic ships and controlling empire/warlord planets gives you those factions ships with the only exception being starfighters they will only use the current best in each category anti-fighter, anti capital ship, all-rounder. This faction would also only be allowed to deploy 3 SSD's and only after capturing Kuat or Mon Calamari (mon cal for the end game variant mon cal style SSD) the reason being their ability to have a more varied fleet makes more effective support fleets. At Tech Tier 5 they would finally get some unique ships of their own based loosely off of a combination of all the major factions styles this would be up to the devs to come up with using their imaginations, but here is an example to help the creative juices flow, A Star Destroyer III class it looses the obvious SD style bridge and is elongated and flattened just a little, This star destroyer would Be a combination of the old star destroyers and the mon calamari by having the shield overcharge options and no obvious shield generator to attack while still having a tractor beam, Only one ability could be used at a time with them sharing a cooldown. Another example would be a Venator styled carrier but with the firepower of an SD I but instead of having the regular fighter that eventually runs out they have and ability to spawn fighters infinitely as a cooldown ability, the reason for the is a regular Venator can carry about 420 fighters but these new variants would have an even larger fighter bay. But those are some examples up to the devs to come up with what they would want for what would essentially be their dream ships.
First off, thank you for the suggestions.
But...
The GCs that use all 5 eras are the hardest to code and use the most story events, therefore would be the worst idea to place this faction into.
Also a faction like that would be incredibly hard to code into. For starters, we would need a variant for every single unit to begin with with the added requirement to be the planets, which gives us the next problem.
There is no such thing as Imperial, republic or warlord planet. During the time period planets changed owners more time than one can count, not to mention that sooner or later almost all of them became either a small number of Imperial Remnant while everything else would be part of the New Republic.
And since planet alignment changes from GC to GC there is no clear line of where to build what, and that have to be unified for the units.
About the uniqe units you suggested, both would be extremely overpowered and would be non-canon(legends) units. There are plenty of ships to choose from which are canon, and we have no real need of ships in these terms.
Also each ability is considered it's own thing and to my best knowledge it is impossible to rig them together with a common cooldown.
About the SSDs, the Viscount is already a little bit of a stretch to be there since it started service after our time period ends, and you would also have a different unit limit for the units, therefore you can have 3 executors and 3 viscounts which already in on itself is extremely overpowered.
Also since other than the 3 main factions(IR, NR, EotH) can have story scripting there is no way to lock out units in later eras, so even what is just an era 3 unit for IR could be built in era 4 and 5 too and we can't do anything about it. And I am thinking in the OP-nes of being able to build Praetors and Allegiances at the same time with just one IR and one Zsinj or Maldrood planet.
Also where would that faction start?
Let's just say this bleeds from more wounds than someone sleeping together with a cactus...
About the new mechanic, we did some experimentation with it in the past(see the Katana fleet mission in Thrawn Campaign) but it is extremely hard to pull out.
We are still have feelings for this idea though, but it is somewhat less than possible that it can be implemented in a random space battle. But who knows what the future might bring.
no
Come on. A bit of niceness never hurts
At least tell the guy why do you think it is a bad idea.