I think its ironic we're joking about Brock, because I suspect Lumir is a red herring the author keeps deliberately giving false signals about and she's actually a Brock type character.
Brock is meme'ed as an idiot these days but he was the guy who was the source of like 90% of the party's pokemon battle knowledge during the arcs he was present. He always had a bottomless bag full of food, treats and treatments for everyone, took care of every pokemon like they were his children, and eventually become a pokemon doctor.
This guy was actually the goat when everyone thought he was a fool.
Lumir is just a bit too obvious in her suspect behavior. I think she really does have a benign stake in the country, plus wanting to help Jelly.