Which ones “dont even exists yet” and are Purely Concepts ? As far as I’m concerned only three vehicles in the Tech Tree has not been shown in physical form, and those are TİYK Projects. Technology Demonstrator thing on the other could be partially true, but If you mean “mock-up” or non-functional vehicle by demonstrator, there is zero Mock-Ups or Non-Functional vehicles in the current form of the tech tree. There was Altay MTR which had mock-up turret but it is long gone.
Please do point me the vehicles which do not “exists”, I’ll more than happy to provide more information.
Let’s be real here for a second, that is true there are complete c&p M60s and Leopard 1s there absolutely no denying. What about the whole families of light vehicles though ? Or Anti-Air vehicles which puts even big three into shame.
You statement is not entirely wrong but you could make the exact same argument for pretty much all the other minor nations. Amount of interesting stuff surpass c&p M60s and Leopard.
Thing is only justified addition to Israeli Tech Tree would be Sabra, not even other M60 modernisations, rest has no ties to Israel whatsoever. Even then, Israel does not need Turkish M60T/TM or other modernisation packages since there is approximately six Sabra variation that is could be added and purely Israeli. If you are curious those would be:
Plus amount of Turkish vehicles would drown Israeli ones and Israeli Tech Tree would lose its identity eventually. That is not a how Sub-Tree would be, a proper Sub-Tree should support the main nation and fill the gaps wherever there maybe. Best Sub-Tree option for Israeli in my opinion is @Chilean_Thunder 's Chilean Sub-Tree Project. Again, there is no vehicle in the tech tree is related to Israel other than M60T/Sabra Mk.II and there is no other proper connection between Israel and Turkey at the moment justify such concept.
How so Turkey needs a Sub-Tree ? What do you deem missing may I ask ? There is two Main Battle Tank Branches, one Anti-Air Branch with not one but two top tier vehicles with different characteristics, a proper and dedicate ATGM platform, option for unique Sub-Tree and a Light Vehicle Branch with both tracked and wheeled platforms also different armament options to fit your play style. Considering our project is mostly focused on high tier and top tier there is nothing missing especially 9.0 onward.
Plus there is already an option for Sub-Tree, Kazakhstan. And unlike any other Sub-Trees, Kazakhstan Sub-Tree only has vehicles related to Turkey and/or Turkish defence firms. We’ve especially excluded anything that is not related to Turkey.