As to the circular craft, it would be difficult to manage (as would the Ark as described (more like a raft). But I’d wager the circular craft would be the more difficult.
However, as I read the Bible the Ark wasn’t all that ‘controlled’ as a surface craft. It floated atop the waters, then “came to rest atop the mountains of Ararat”. That doesn’t imply control. With that in mind, either style might have worked, but I go with the Bible every time.
I recall a relatively recent test of a scale craft built to the Biblical proportions, in a wave tank, somewhere in Asia, possibly Japan.
I’m recalling that the proportions were nearly ideal for preventing roll, pitch and yaw on rough seas, according to this research. Nearly ideally stable, in other words.
A circular boat would spin rapidly in such chaotic waters and currents creating an unlivable centripetal force...think of the the ‘centrifuge type” ride at an amusement park or county fair.