I have towed my HP16 with a Schreder Trailer with my father in-laws
Ranger.
It towed just fine. He tows his boat with it all the time. A Ranger
should have no problem towing a glider trailer. I personally don't
care to tow with automatic transmissions but this is just my
preferance.

I haven't towed with the S-10 but Towed one of the Kitfox Factory
Demonstration Trailers (20ft+ enclosed Trailer with a kitfox inside)
with an S-15 from Oshkosh to Boise. it towed great.

Brian