Kris,
If you are going to use more than one motor then all of them should be the same motor (prop too). If one ESC is used to control all motors there can be a very slight difference in motor speeds, which is fairly typical. Rudder 'trim' should handle it. For multiple ESC/motor combinations, if all the ESCs and all the motors are the same, rudder trim should be able to handle that too. Some ESCs have adjustments to bring motor speeds at least 'ball park' close. Then, (your right!) rudder trim.
Worried about one motor wearing out faster than the other one? Don't waste a lot of good 'worry' on it, it'll probably live longer than you will, or at least your interest in that particular boat - lol.
- 'Doc