I would think a short femur would do better with a short crank than a short tibia.

But, as mentioned, the thicker pedals, some lift in the shoes, etc, could also potentially help.

I think I've read that the experience with other cyclists is that somewhere around 50% correction works well. So, for a 1.5cm leg length difference, you really only need to correct the length by about 0.75cm. And, adjusting the crank length is by radius, so even less than that.

So, 165/170 would be 5mm difference in radius and 10mm in diameter, and would probably be an adequate change. Especially if you add in a little extra lift with the sole, pedal, etc.

or 170/175mm, etc.

If you're buying basic square taper cranks, your local bike coop should have piles of them (if they are open). And, they don't have to exactly match. Most square taper cranks have the square on the diagonal, but worth checking. And, make sure the Q-factor is close.

At least using used or co-op cranks, you can test out your configuration before you dump in a lot of change.