Valverde had come up through the ranks today I think he would have been pushed toward being purely a GT hopeful. He's got incredible punch to win stages at the end, can handle really long races/stages, and has always been at fighting weight. The knock against him in GTs has been long climbs at altitude, or something like that, but training methods have advanced since the last century and I could see him winning all 3 tours in a career with a WC RR or two, but fewer one-day victories.
He's also been something of a lone wolf, but he might have been reined in under a structured team like Ineos. Fun to speculate either way. For this Vuelta his time may have passed but certainly a podium is possible if the chips fall his way.