Well, Tops IS a fair deal older than Tria; it was revealed in movie six that he has grandchildren; Tria just had her first child.
Yes, while Tria is indeed weaker and softer than Tops, she probably has better circulation and stuff... and is more relaxed and pleasant to be around than him...
In a sense, Tops's strength, toughness, and austerity are balanced by Tria's weakness, softness, and hedonism... yes, his strong muscles vs her loose muscles... Tops is good at getting others fired up (movies 3, 5, 7, 8, 11), while Tria is good at calming them down...