Here are some things I do for ours at work (I work in fundraising at a nonprofit). We do a holiday drive for the homeless families that we work with. Not all of this may apply to your drive but here are some things that we do:
1. We collect wish lists of wants and needs. Each wish list has a few things on it - typically a couple needs like snow boots or a jacket and a want or two like a game, doll, etc. The wish list also has sizes, favorite colors and age and gender of the kid. Since we know the families/kids in advance, this is easier to do.
2. For some of the families, the staff will split up and buy stuff for all the kids in a family.
3. I always set aside several of the families and reach out to local businesses and ask them to sponsor. Then the different departments at that business will each adopt a family and buy all the gifts.
4. By working with the whole family, it pretty much guarantees that each kid in the family has about the same amount spent on them (since people really care about fairness naturally) and that both older and younger kids get stuff that they want/need.
5. Often the businesses will decide to go above and beyond and also get gift cards for groceries for the family. This isn't required, we don't suggest or ask but it just naturally seems to happen. I know the companies get really into it and feel really good about it. They don't ever even get to meet or see the families and they still like it.
I know it's a lot more work this way to organize it but I do think it results in a more successful outcome in the end. I don't necessarily know how Cub Scouts could participate in this. Maybe if you worked with local businesses the Cub Scouts could be the ones to approach the businesses and then collect the toys at the end? You could make up a flyer that they could use to solicit participation. You could maybe work with a specific nonprofit or church that could identify families in need rather than just a mass toy drive?