This would be a good domestic match up but I believe Liam Williams is a world class fighter at this point and will soon be challenging for world titles.
Liam Williams is an insanely aggressive fighter that puts on great pressure and clearly has good power. His defence is surprisingly solid considering how offensive minded he is and while he can be caught coming in no ones really done it yet.
Andrew Robinson is a solid domestic campaigner who recently sprung a big upset in Poland versus a fighter that was 41-0. His defence isn’t great and he doesn’t have that much power.
I think Liam Williams wins this fight by knockout in six rounds because he has a lot more power and at this point is a world level fighter while Robinson is domestic level.