paddle tires like in the vid need alot of power thru the driveline which in turn is punishing on the clutch , as apparent in vid. the stock motor is working (but struggling )definitely need more than stock for real rip power with that setup.
so the more power thru the driveline the MORE power is needed to turn the tires effectively, thats why 2 servos will give SO much better action.
one servo will work but ON throttle steer will be pretty weak if not absent at times especially with solid power (like 5-6+hp) .
cool thing about hobbying models like this is you can make whatever u want . and making a DR with dual servos is kinda what your choosing with big front paddles. lotta room on the model for dual servo mod steering , ganged together or separate.