Description mentions that Each array includes only integer numbers. So, empty arrays should not be considered. Also, arrays of different length do not affect how such problems are solved, so I would say it is more on perspectives. Plus, unifiying each language in terms of test cases can be difficult because translations can be done by any user once they reach a specific honor threshold, though efforts on improvising these have been done more actively lately

Some languages have such tests. This constraint isn't mentioned in description, but the author probably chose equal arrays anyway. I don't think it would impact the rating at all.

I passed performance and your test and still failed a very small number of tests that were too big to debug by hand but pretty small in general (like 10x10)

Yeah you're right i should include those in if/else above, thanks :)