Sounds fair, but how do you know the control surfaces that we see on the J-36 are insufficient for traditional fighter levels of agility?
I don't know for certain. Maybe what human understanding of aerodynamics have improved that much where we can achieve similar levels of agility without stabilisers and canards now for these next generation. But looking at Shenyang's where there are likely moving wingtips, additional control surfaces on the top of the wings and canted stabilisers, that would suggest the best aerodynamicists can do to match 4th and 5th gen agility without vertical stabilisers is SAC's approach with numerous control surfaces that can be brought in when needed and cruise flat when not.