Blaine County set the bar for rural GTA - Sandy Shores, Paleto Bay, Grapeseed, Mt Chiliad. Leonida's countryside is different in flavour. Comparison.
Geography
Blaine County is desert-and-mountain. Leonida is wetland-and-flatland. Different landscapes producing different gameplay - traversal in Blaine was about elevation and dirt roads; in Leonida it's about water and saw grass.
Density: Blaine was deliberately sparse. Leonida's rural areas, based on trailer aerials, may be denser - more visible buildings, more visible activity.
Towns
Blaine had Sandy Shores (trailer-park-coded), Paleto Bay (small-town-coded), Grapeseed (farming-coded), and a handful of micro-settlements. Leonida's named-town situation is unconfirmed but trailer aerials suggest a similar pattern.
Whether Leonida's small towns can deliver the kind of memorable side content Sandy Shores did is open.
Gameplay vocabulary
Blaine had off-road driving, hunting (limited), Mt Chiliad mystery hunting. Leonida's likely vocabulary is airboat traversal, beach side-content, possibly fishing, possibly hunting.
Different sub-genres of rural gameplay; same general category.