Last setup before switching ultimately to floor units was a 5U rack AxeIII along with an RJM22 in a flight case, the flexibility and ease of use was always at 110%! But so was my back when carrying all that weight to rehearsals and gigs.
When the FM3 was introduced, I immediately jumped on the wagon, switched all that mighty setup for 3 switches.
Shortly after I realized how radical that switch was (22 buttons down to 3!) so added an FC6 but still, I wasn’t 100% happy because of the lag on preset switching back then.
So, when the FM9 was introduced, I knew it is what I needed, and it is! I've switched from the 3 to the 9 and by that, my search for a Swiss knife without compromising on switches and also reduce so much weight, was over.
I wish I could shrink my setup to 3 switches but I can't due to the current band I'm in which requires more than 3.
There are no rules, the 3 is great and if you smartly use the CPU, you can get whatever you need out of this unit.
For me it was more a problem of the switches rather than CPU capability.