It's good to see you, Herbert!

I understood your explanations about arrangements. I agreed.
--------------
The LH chords on the accordion are fixed in construction, not flexible.
--------------
That's where you're wrong, my friend. Have you ever tried to play 'combuned' chords? For example: C + Gm, or Cm+Cdim, or C+Am.
Also, I use to play pretty often chords with the 'wrong bass': F(bass)+Cm(chord), F#(bass)+Am(chord), C#(bass)+G-7(chord) et cetera...
There is the endless amount of combination! It IS very flexible, believe me.

Be happy.
Kombrig.

And take a look to the 'Classical'.