Oh I've just noticed that within the datasheet.
Just one more question before I investigate the voltage drop. If I have the DRV8848 paralleled and I don't correctly configure the chip for this operation, what state could the chip be in? I think in my next revision, I will just simply tie the SLEEP pin to my 3V3 rail, as this fixes the issue which I'm facing (although I really would like to know why). I will have access to my board later on this week.
Thanks