I love analyzing the suspense plots. In the Montana Heat series, the threats are often large-scale—arson, drug rings, kidnappings. In Montana Men, the dangers are often more personal—stalkers, secrets from the past, threats to the ranch. The Wilde series blends both, with personal vendettas having corporate consequences. Reading them grouped by series lets you appreciate the different scales of conflict Ryan explores.
It's like different subgenres within romantic suspense. So choose your series based on what kind of threat excites you most: large-scale criminal investigations, personal/local threats, or high-stakes corporate/family drama. Then read that series in order for the best experience of that particular subgenre.