Who could be better accountant, men or women?

One who knows Accounting better.

There should be no gender bias. I'd hire the Accountant based on their educational background

Regardless of their Gender, Anyone well versed with Accounting, has the right skills for it and quite possibly the experience to deal with work/assignments.

There should be no gender bias. I'd hire the Accountant based on their educational background, previous experiences and their skill set and familiarity with modern accounting and statistical soft wares / tools.