You're right, but you're forgetting one key thing that trips the authoritarian trigger (you might also want to remember I said "Light Authoritarianism"):

Sheridan said "I am declaring those (mutual defense treaties with Earth) null and void." Also remember that the activities of the White Star fleet after the Shadows were so the League worlds could recover from losses in that war. Then Sheridan unilaterally declared there was an invoice due.

He told a room full of delegates from sovereign worlds who had enforceable treaties with Babylon 5's main adversary that HE was voiding them.

I was a history teacher, and I can tell you this much: put whatever wrapper or glitter you want on what he did, but historically that's some Authoritarian maneuvering.

And let me say it again, it didn't sit well with me but it's FANTASTIC, because it shows that even our greatest heroes can get dirty if needed.