Arm selected + unarm all other tracks?

Hi.

Question:
how can I arm the selected track and unarm all other tracks with one button press?

Context:
I've managed to get a button press on my MIDI Fighter 3D to arm the selected track, but I'd like for it to also unarm all other tracks. I've got a Push 1 connected, and Live set to exclusive arm, so selecting a track when no other track is "properly" armed will "soft arm" the track, for lack of a better term. 90% of the time, I want this behaviour, but sometimes I need to "hard arm" a track because I need to have a different track in focus while recording, but I don't want "hard armed" tracks to stack; it slows me down when I have to look at the screen to find the other track that is armed and unarm it.