Agree too The melodeon looks to be a right hand instrument, with some chords, but that's not the way it's played.
Agree to some extent but also disagree.
It depends on your style of playing. It is perfectly possible to treat the instrument as right-hand, melody dependent and using the basses and chords more or less automatically, without too much thought or analysis, depending on which RH row you happened to be playing on. Many traditional English players did this in the past, morris musicians and East Anglian players particularly, and continue to do so today. In contrast, continental players tend to learn smooth cross-row style right from the start using 'correct' LH harmonies. Both approaches are neither right nor wrong, they are just different and perfectly valid.