Let's keep in mind that the O.P. is talking about towing a 15' trailer that weighs about 2300 pounds dry. Even presuming he could fit in/on another thousand pounds, road weight likely can't won't exceed 3500, max.
Without knowing the exact specs of the tug or what else he might be carrying in it, 2008 Ridgelines are generally spec'd at around 5,000 tow pounds. I think adding on a weight distribution system for 350 pounds or less of tongue weight may well be more trouble than it's worth.
You MIGHT need a simple friction sway controller, but the only way to determine that for sure is to properly load the trailer for the road and test it with the tug. The trailer's P.O. said he didn't use/need any such add-ons; but driving habits differ and this may prove different with this combination.