I just got through with a newspaper combine of two colonies...a queenless and queenright colony. Our swarm season is about past, though, so I'm not sure how that will affect your combine.
The queenless colony had a fairly large population and was working hard...already drawn and in the process of filling two 8-frame medium supers...nectar, honey, a little pollen...but no sign of a queen or any brood after three weeks sitting on the hive stand. It was situated between a small (swarm) colony and a medium sized established colony.
The queenright colony was a small colony that took up about a third of an 8-frame super. Not big at all. The queen had roughly half of three frames filled with brood...these bees were working hard, too, but there was just so few of them. It was situated between two strong colonies.
I figured both groups of bees were energetic and wanting to build up...but one had a small workforce and a laying queen, the other one an energetic workforce but no queen and was beginning to get a little "rowdy" (but no drone layers).
I put a sheet of newspaper on top of the queenless colony where it was sitting and moved the queenright colony on top of it. No slits in the newspaper, no spraying to dampen, or anything...just a solid piece of dry newspaper. I closed it up. This was on Monday of last week.
The following Friday I checked the combine and found that the newspaper that was inside the hive was gone. The three half frames of brood had expanded to over three full frames (with a nice pattern, too!

). And they've been "busy as bees" since then. I think these bees are going to build up into a nice colony.
Personally, I'd go ahead with the newspaper combine...the longer you wait with the queenless group the the more resistance you may meet from them. There's a risk, of course, as "bees will be bees and do as they please". Your decision.
Best wishes,
Ed