As long as you can overcome the drag of all the planes and maintain a speed faster than the gliders, you can do it.
My glider could easily be pulled up by a standard Wot 4 with a 46 on the front. However, when learning to tug (leave it!!) having lots of power allows you to get up to height and out of danger very quickly.
I'm up for giving multiple gliders a tow. I guess if Bret joins me and you Steve, we could have a threesome?