There is a parameter known as share difficulty. The pool sets the share difficulty.
For example,
Your rig1: 1x 1080ti (750sols)
My rig2: 1x 1080ti (750sols)
Let's say the share difficulty for your rig from the pool is set to "2x", so you'll be getting "y" amount of accepted shares. The reward for one share at "2x" difficulty be "2z".
The share difficulty for my rig from the pool is set to "x", I'll be getting "2y" amount of accepted shares. The reward for one share at "x" difficulty be "z".
So, no matter if your shares are low and mine are higher, we will probably mine the same amount of coin as it all depends on share difficulty and accepted share proportionally.