IMO, it doesn't really affect anything that the pbase knows these or not. Not in any meaningful ways, anyway. Does it matter how many gnomes are rolled? Then you see there's two or three warriors active. Nobody's going to roll a gnome warrior because their numbers are low.
The qthing is slightly better in terms of player info, more of a chance to get that demon DK if there's not already one running around. But that doesn't mean that the staff might not make an exception.
Or, novel idea, post on prayer asking if there's a slot open for what you'd like to go for. This would serve two functions as it would let you know if the slot you're hoping for is open (or anything else that might help/hinder you), and inform the staff that you're interested so they can start watching you for said slot.