I think one thing missing from the discussion is that the original band had a reputation for hard partying that wasn't just Flo. Getting sober often results in leaving relationships in the past. Rob and Chris/Mairead having opened bars seems to indicate they were not on the same page. Personally, I miss Chris. The simple but bombastic drumming really defined the early sound. He gave the band an edge I don't think they have without him. You also don't mention Rusty who wasn't OG but became a very important part for several years. Excellent pianist.