I prefer to have my bananas on the right control stick and moved my jump button to the left bumper (Halo's Bumper Jumper setting), but this is also a good suggestion.
Anything that keeps your fingers on the controller during combat will help.

@guepard4 AH! Silly me! Misread the OP!
Yeah I only use R Stick for banana, so could easily switch to the A button... might have to try it out!

@sshteeve dijo en TIP: How to fight and jump like keyboard/mouse players using a gamepad:

@guepard4 apologies, I have updated my original post as well now, but basically:

Normally you would use the R trigger to either slash the cutlass or to fire a gun. My question was which button you then use for that instead (given that people would also want to still fire or slash when in the air and moving)?

No no, I am talking about pressing the Right JOYSTICK, not the R trigger.

R trigger would remain for firing and slash.

@guepard4 apologies, I have updated my original post as well now, but basically:

Normally you would use the R trigger to either slash the cutlass or to fire a gun. My question was which button you then use for that instead (given that people would also want to still fire or slash when in the air and moving)?

@sshteeve What do you mean with fighting control? (My game is not in english so maybe the translation is different)

@guepard4 not the first time I have heard this and an interesting idea. What do you set your control to for the fighting action (slashing cutlass or shooting the gun) to though instead? A stick-click or a bumper instead?