Both basically have the same torque, theres no free lunch. The 700 lbs-ft engine is obviously twice the size and turn half the rpms then the 350 lbs-ft engine. So for every one revolution of the larger engine the smaller one is doing two. Torque is basically a snapshot of one revolution and hp is them all added up over time. So if you look at both engines here there both doing 700 lbs-ft in the same moment. 1 x 700 = 700, 2 x 350 = 700.
To access the smaller engine potential we would need about twice the gearing which would put the same torque to the ground.
So both engines have the same hp and torque. Again the better hp curve should win.
Thats why we use hp to compare motors it takes acount of all the torque an engine produces not just one revolution.