T-34-85
We decided to take a different approach with Medium Call-ins and have them tie into the core tech tree. This change still require the player to have commander equipped with a T-34-85 Commander ability but also will now require players to build a Mechanized Armor Kampaneya to acquire the T34-85 medium tank.
- T-34-85 is no longer a call in vehicle
- T-34-85 is now buildable in the Mechanized Armor Kampaneya
- CP changed from 9 to 0
Sherman Easy Eight
We decided to take a different approach with Medium Call-ins and have them tie into the core tech tree. This change still require the player to have the Rifle Company Commander but also will now require players to unlock the Battalion Command Post to acquire the M4A3E8 Sherman ‘Easy Eight).
- M4A3E8 Sherman ‘Easy Eight’ is now a buildable Tank in the Battalion Command Post
- CP requirement reduced to 0
https://community.companyofheroes.com/discussion/67/coh-2-changelog/p3
Since then, several vehicles were tied to tech as well, but not all of them. Usually, it was made for nerfing meta doctrines (like it was with Puma and shock rifle doctrines) or to put more units in the doctrine (like mech company). I think last variant of this mechanic (call-in with CP and technology requirements) is the way how all doctrine vehicles should work in the first place.
Currently, there is no clear system for call-ins. Especially for light vehciles, proportions are circa 40% vs 60%. At the same time heviest and mediums have different mechanics in general (mediums mainly tied to tech, heavies mainly call-in with tech requirements)
Light vehicles
In total: 14
36% - tied to tech
64% - call-ins
M5 with Assault Guards - call-in
Opel Blitz for Ostheer - call-in
SdKfz 250/1 - call-in AND tied to tech (depends on doctrine)
SdKfz 250/7 - call-in
SdKfz 234/2 "Puma" for Ostheer - tied to tech
Opel Blitz for OKW - call-in
SdKfz 221/223 - tied to tech
WC51 - tied to tech
M3 halftrack for USF - tied to tech
M5 halftrack for USF - call-in
M21 - call-in
Valentine - call-in
M3 halftrack for UKF - call-in
M5 halftrack for UKF - call-in
Medium vehicles
In total: 12
75% - tied to tech
25% - call-ins
T-34-85 - tied to tech
M4A2(76)W (a.k.a M4C) - tied to tech
Panzer IV Ausf. J for Ostheer - tied to tech
StuG III Ausf. E - call-in with tech requirements
Command Panzer IV Ausf. F1 - call-in with tech requirements
M10 "Wolverhine" - tied to tech
M4A3(76)W - tied to tech
M4A3E8 - tied to tech
M4A3(105) - call-in with tech requirements
Flammpanzer 38(t) - tied to tech
Ostwind for OKW - tied to tech
Achilles I - tied to tech
Heavie vehicles
In total: 16
12,5% - tied to tech
87,5% - call-ins
KV-1 - tied to tech
KV-2 - call-in with tech requirements
KV-8 - tied to tech
IS-2 - call-in with tech requirements
ISU-152 - call-in with tech requirements
Tiger I - call-in with tech requirements
Tiger I Ace - call-in with tech requirements
Elefant - call-in with tech requirements
M26 - call-in with tech requirements
Jagdtiger - call-in with tech requirements
Sturmtiger - call-in with tech requirements
Tiger II - call-in with tech requirements (added due to in-game mechanics)
Command Tiger I - call-in with tech requirements
Command Panther - call-in with tech requirements
Churchill AVRE - call-in with tech requirements
Churchill Crocodile - call-in with tech requirements
In total: 16 out of 42 working not as call-ins. Or 38% of doctrinal vehicles.
If this change will be applied, all vehicle call-in will work in the same way and have common requirements system. Actually, i think panzerfusiliers should be adjusted too, because it is the only infantry docntrinal unit, which was tied to tech.