I've been having issues where the the combination of AI allies for a solo Raid Battle just... aren't effective. I've seen multiple 7 star Raid Battle explanation videos say to "reroll for an Intimidate user for better results against physical Pokemon", but I have no idea how to do that. I've had situations where, despite doing nothing but circle-clearing the Raid dens on my map, I get the same 3 allied Pokemon for a full day. I've had other situations where 3 Raid dens in a row I get 9 different AI allies.
What is the mechanism that determines what AI allies are provided for solo Raid dens? Can you force it to reroll? How?