I can kinda see what you're saying ...
Lucille to me has always been Speedy's 'girlfriend', not Guido's. I think Guido just likes to keep Speedy on his toes

They're always going to compete, that's how they are. They're like brothers. They'll fight and bicker but deep down they love eachother (in a strictly, brotherly kind of way of course - minus the KNT Gender Bender episode where Speedy went a bit fruity for Guido).
But yeah, Guido seems to fight less with Speedy as the series goes on. Maybe he was over Lucille? Perhaps he was falling in love with Polly? He did ask her to marry him only two episodes away from the 'Great Comet Caper'. Mind you, that is a biased and very subjective view of things on my behalf
