Help with building RC controlled mecanum wheel robot

Hello! I am new here.

I plan to build a RC controlled mecanum wheel robot. I do not have much experience with coding, but my intention is to use the SDRobots Github code found here: https://github.com/SuperDroidRobots/RC_Mecanum_PWM/tree/master/RC_Mecanum_PWM

First I need to ensure I have the right part list.

Motors:

I have four geared motors with encoders. Since this robot is going to just be a RC controlled, I expect it is possible to just not connect the encoder wires, and drive it as a normal DC motor. Will this work just fine?

Motor controller:

I plan to use two dual Sabertooth.

Microcontroller:

I have an Arduino Uno.

Radio controller and reciver:

I have a couple of radios I have used to RC planes and mulitcopters. These have only one centered stick. Will this be just fine? Does the brand and type of controller affect the code?

Battery:

I plan to use 3s LiPo battery or a plain lead battery.

Do I need any other components? In line 29 in this code https://github.com/SuperDroidRobots/RC_Mecanum_PWM/blob/master/RC_Mecanum_PWM/hardware.h in line 29 it says “Output signals for TTL Relays” Do I need some relays?