Multiple Motors and one H bridge
As a general concept I don't see any problems, as long as you don't expect the robot to move in a perfectly straight line. It may well be pretty good, but you seem to be aware of the problem of motor/wheel matching.

And I presume you are aware that the motors on the left side must be wired the reverse of the motors on the right.

When you graduate to differential steering, you will need 2 bridges. Get used to it. Actually, since you are talking about 4 motors I assume you have a 4-wheel vehicle with a motor on each wheel. Be aware that differential steering works very poorly on 4-wheel vehicles.