I've been pondering this question for quite a while. If the Male version had both cannons and machine guns, what was the point in creating an exact copy solely with machine guns?
The male versions were intended to knock out fortifications, pillboxes and so forth, while the female versions were to suppress or repel enemy infantry.
The cannon is not terribly effective against infantry in open terrain so it was thought that replacing those gun mounts with machine guns would be better suited for the role.
They were different configurations for different purposes. The cannon (6 pounder gun actually) in the Male variant took the place of machine guns in the female version.
The guns had a slower rate of fire and packed more punch, so were better for dealing with hard targets like fortifications and other tanks leaving the machine guns to primarily defend the tank.
The female versions had more machine guns so were better for dealing with infantry, kind of like a mobile machine gun nest. Remember back then machine guns were primarily static weapons that required 2 or 3 men to operate efficiently, so the ability to make them mobile was a big advantage.