4 of them!?!
Never happened to me, I have seen some with 2 fire and 2 musketeers but not 4 fire. I guess the Full Bondage Mask is our only hope, especially if paired with Anklecuffs and the Musket of Helplessness.
maybe I'm remembering things wrong and it was two Slime Gunners or a large one, all I remember was that one encounter destroyed me and I've been scared of them ever since.
I did find a counter to them though on a veteran mission with all novices, get a noble with high reflex save and have her spam "Appel," the noble I had had 18 dex and a condom mask, (I think red is reflex and the black one's fortitude,) the slimes kept trying to set a status to an enemy that could dodge, riposte and shrug it off if they did hit
2 words, forced riposte. :)
But yes, if you don't have that hypnotic suggestion then killing them quickly is your only good option. Having everyone use AoE moves to get through the dodge tokens is a good way, other options includes the maid's (enhanced) feather duster or the mage's magic missile.
They also lose the dodge tokens when they grow, focusing on one of them as soon as it does is a good idea.
Encounters against the small Vines are ok, but if you're fighting multiple Alarune Horticulturalists with other opponents they can stack up Vines in the Reinforcement queue, which looking back probably just needs good target priority.
There is a 4 Clustered Vines encounter however, and the turn queue at the top had 20 slots due to the multi hit attacks. It is an ELITE encounter though, so I'm not shaking in my boots at this one, but yeah I am definitely not fighting that again.