I’d be reading up on Subwoofer placement, and the physics of sound, were I you. There isn’t a simple ‘one solution fits all’ here. 

And add a Sub or two to your Arc. 

Right now, I have a Mini Sub and two 300s.  Would two Subs give me what I’m looking for, kicky not boomy?

The two 300s, set up as surrounds, have little to nothing whatsoever to do with bass. Different placement of your mini might make a difference, which is why I was suggesting some research. 

Just to quickly mention you cannot add two Sub-Mini’s, only two larger Sonos Subs can be used and one of those must be a Sub (gen3).

edit: I would go along with what Bruce suggests and try your Sub-Mini in different locations in the room, try it with Trueplay both enabled/disabled and adjust the EQ and Sub volume settings etc. until you perhaps achieve the output that suits how you like to hear things.

Hard to know exactly what you mean in kicky vs boomy.  It sounds like you’re referred to sealed (probably kicky), vs ported  (probably boomy) sub, and maybe googling the subject will help you get an idea of which one you prefer.  The consensus typically is that sealed is better for music while ported is better for movies.  Sealed also uses more energy to produce than ported typically.

Sonos Minis are sealed, while the full Sub is ported.  You can only use 1 Mini with the Arc though, and it produces less volume than the full sub.  2 minis is less than a single sub.  You can use 2 subs with the Arc.

The Arc, without a sub, can’t reach the same lower frequencies as the sub, but still gets pretty low.  Don’t know the frequencies off hand.  And it probably would be considered as sealed for the bass frequencies, but could very well be wrong on that.

Here’s a bit of my research…”As a bass player maybe I could clear this up. =D

Boomy and punchy tend to describe the "attack" of the bass. If you can't make out the attack, that's boomy, and tends to happen when the sound is entirely low frequencies. Punchy is having more attack to the sound, and requires higher frequency response. Believe it or not, having good midrange speakers can accentuate the percieved attack of the subwoofer.”  

Yes, my car’s sub is sealed and gives that tight, clean bass and not at all sounding “separated” from the rest of the sounds, which is what I tend to feel with my mini.

You are talking two things - one, bass minus the bass bloat. And two having the bass integrated with the rest of the music. 

My Sonos set up is obsolete, but sounds fine and it consists of a play 1 pair with a Sub. I have the defined bass that sounds natural via Trueplay tuning; toggle that off and the bass immediately loses definition. And I have the Sub placed between the two speakers in the same plane to get it to integrate with the play 1 pair.