Why would you lock the flamer upgrade behind a doctrine? If anything, this is the most attractive part of the unit and it synergizes perfectly with the flak ht which provides suppression allowing the flames to burn more effectively.
Emmm……normally,Ost build 251 need 10+40+20+30-20 (80)fuel,for OKW,it need 15+25+30-10 (60)fuel……no limit for Flamethrower 251 will too OP……and I also want same unit will different for Ost and OKW