I too have taken the reins of a Beaver group - 24 of 6-8 years olds - 50% of whome are a nightmare..........
I volunteered to help about 3 years ago as the leaders were really struggling (parent helper) - 2 full time leaders, stuff in their own lives etc.etc, meant we needed a minimum of 2 - ideally 3. I got involved, but both leaders have had to stand down due to commitments, so I said I'd carry on running it (still not a fully fledged leader - no training etc)....
As part of this I sent letters out to every parent asking for help - no help, no Beavers..... we got 2 parents who could do most weeks and another who would help out if needed - at that age, you just need extra pair's of eyes as little Jim and John start to kick the crap out of each other in the corner as a game is going on.....
I'm getting polite but blunt with new parents now - get folk saying their child has been on the list for months - I explain we are at capacity (24 is the maximum pack size and not 'really recommended' at that age....) and that we have that many on the waiting list that we could start a second pack if we had volunteers.
So, when any one explains, tell them you've got enough kids at the moment, but they are welcome to help out, then we can boost the pack size....
The main thing is, the kids have fun - that's number one, so if you haven't got enough help, you can't keep an eye on them.
Most weeks we have two or three adults, and two 15/16 year old Explorer Scouts - you need it with that many lads.....
I go home with a splitting head, and a sore throat each week - it's that LOUD.
As it stands, I had to close Beavers last week as I had a hospital appointment, and it's likely I'll have to close it for a month when I get my shoulder fixed in Spring - the othr 'parents' don't want the responsibility.
As a group we are very 'inclusive' and have one lad in Cubs (who has recently left Beavers) and a new Beaver with learning difficulties - both similar problems, and need a helper with them.
Despite it being seen as a 'baby sitting service', you do get a lot out of it, and you hope you can make a bit of a difference to the kids.