Engine mounts are not designed for a 200 - 300 mph side load at takeoff thrust.
I'm sorry, they just aren't. The tail wasn't even designed to withstand exaggerated pilot rudder inputs.
If it was at cruise altitude and throttles were way back and the tail came off, they might have hung on longer.
You are missing the reason the tail fell off. The engines fell off because you can't fly an engine cowling sideways. The engines are stuck on pretty good. Frogbus engines are NOT designed to come off in case of a gear-up "landing." And that carbon fiber tail is pretty tough too.
SO unless you have TWO good reasons for large surfaces to come off, you have to conclude the ONE good reason: they don't like to fly sideways, is the ONE reason large surfaces came off the plane.
This is actually common in air crashes where the plane is out of control: loss of control, followed by "unusal attitude," followed by large surfaces coming apart. Google up "unusal attitude" and see for yourself.