Garden hose thread (GHT) is a specific size and pitch that is not compatible with any other plumbing fittings. Its design facilitates a secure seal with hand tightening only, under most circumstances.
You really shouldn't need an adaptor to hook up your garden hose to your new pump.
You can always ask the folks at AR by calling them, toll free, at 866-235-5112 about any other applications you have in mind.