I want to start this by saying I do not dislike subtrees. I believe they are a great way to introduce new nations to the game that might not be able to stand on their own as an independent tree. However, that’s just the thing- subtrees should be used as a means to introduce a new nation to the game NOT to just give an existing nations whatever “meta” vehicles are the flavour of the month.
This means that when a subtree is introduced, it should (within reason) all of the vehicles that that nation historically developed and operated. NOT just whatever vehicles are cool or “meta”. After all, the goal is to add the new nation to the game, so you’ve gotta take the good with the bad in terms of what vehicles that nation used. If the goal truly was just to give nations “good” vehicles, then what’s the point of even having national trees at all, just give every player the same 5 “meta” vehicles.
Now some people might say that “that’s too much copy-paste!” Strange how no one seems to complain about copy-paste if it means they get a Leopard 2, JAS-39, F-15, T-55, T-80, etc…
But that’s enough negativity for the moment. For the most part, current subtrees do their job pretty well. Finland, South African ground, and Hungary all do a pretty good job of adding their respective military branches in their entirety. There are of course many missing vehicles, but not abnormally so, and it’s clear the intention is to actually bring each nation to the game. There are exceptions- vehicles like the Hunter F58 or Bhishma introduce vehicles to nations that didn’t develop or operate them, with the implication of a subtree but without the actual tree itself. This just serves to buff the nation with a random vehicle they had nothing to do with, without actually adding anything really new.
But looking to the future, more subtrees seem to completely lose the point of adding a new nation. Nations with far too many vehicles to fit in a subtree (such as Poland or Czechoslovakia) are asked to be added into some existing tree, which will naturally mean the majority of these nation’s vehicles are excluded and the “subtree” is just a collection of “good” vehicles the mains of whatever nation want, with no respect towards the subtree nation or its history. Worse are multi-nation proposed subtrees, such as a Commonwealth tree for Britain, East Asian tree for Japan or China, Eastern/Central Europe for Germany or the Soviets, or the Benelux subtree leaked for France. Each of these have far, far too many unique historical vehicles to be properly represented in the game and only serve to give Britain/Japan/China/Germany/USSR/France mains whatever vehicle they’ve been complaining is OP and needs added to their “suffering” tree. Each of these multi-nation trees could easily be an overflowing independent one, and most are even comprised of multiple nations that could each be their own tree! Heck, just look at the idea of a Commonwealth tree as an example:
3x full crammed trees into a single line...
Canadian Ground Forces Tech Tree
Adding an Australian Tech Tree
Major Update Concept/Pitch - "Call of Mahabharata" - The Indian Nation & Ground Tree
and that’s not even discussing the smaller amounts of vehicles from other nations such as New Zealand!
Any one of these nations would be overflowing as a subtree, though could work. A Commonwealth tree only serves to let Britain pick and choose an Abrams and F-111 from Australia, Leopard 2 and F-18 from Canada, T-90M, Tunguska, and Su-30 from India, while completely ignoring 90% of each nation’s vehicles.
So in conclusion, subtrees should be used to properly introduce new nations into War Thunder. They shouldn’t be treated as a way to “buff” nations by introducing foreign vehicles. Subtrees, out of respect for the game and for the nation, should attempt bring in the entirety of the nation’s military vehicle history, within reason of course. This means that subtrees should always be of a single nation, and additions to that tree should be treated the same as if the subtree was standalone- whatever the country used and developed, without any random foreign kit (such as another subtree smushed into the first). Not just whatever vehicles will placate the angry mains of the “home” tech tree.