I've seen C123 inside staffed about as often as it is unstaffed. I've seen C72 inside staffed slightly less often than it is staffed. Both clubs have always had the outside fully staffed.
I have never seen an (obviously) United agent inside A in probably a dozen visits. The one time I asked the single person there -- sitting behind a miniature Canadian flag -- if she could assist with a UA question she explicitly told me Air Canada only and directed me to the desks outside. (This non-observation includes yesterday).

(On the plus side last time I passed through C at ORD they were actually installing a "Customer Service" sign above the desk inside the club which made me hopeful that UA isn't completely abandoning customer service as deplorable as the current state is)

I get if the inside and outside are staffed travel assistance should be sent inside, but when there are no UA staff inside, and no queue outside (does it really take 3 agents to explain how to scan your boarding pass on an automated gate?) I don't think I'm being crazy or unreasonable to expect that a customer service agent, in a lounge I'm paying extra for, should be able to offer customer service. Heck even if it's a "give me a moment and I'll meet you at the desk inside" if you don't want them doing customer service from the exterior of the club would be fine because I can see why you wouldn't want to make the credential desk look like a generic customer service counter that anyone regardless of club status can use.

"No, I'm just going to keep chatting with my coworkers and tell you to get bent" on the other hand is not what I would describe as an acceptable customer service posture and what I've personally experienced when approaching the ONLY UA agents in the vicinity of both clubs with no queue.