I enjoyed reading your post, although I disagree with some of it.
Cachin, as you say, didn't have any one signature shot and didn't make 'showy' plays to bring the crowd out of their seats, but he was truly great. He did it with perfect positioning, perfect form and hustle. I'd take Cachin anytime.
I also think you underrate Remen and Mendi. Remen was a star at Miami and Hartford, and won the 1991 and 1992 world championships. The 1991 frontcourt field was Remen, Mendi, Bolivar, Cachin, Jauregui, Arrasate, Camy and Beascoechea. Remen and Elorza beat Mendi and Elorduy in a tremendous final. It you watch the video from Larry's site, you'll see how good they were. (Although you were right about Remen's defense: If he didn't occasioanlly drop balls, he would have been beating out Cachin).
You mentioned one of my Bridgeport favorite, Chasio, and his powerful overhand right side. I LOVED that shot. I remember one night, game point in the single point final game, he came up to catch the ball, wound up but threw a dejada instead. The frontcourter had gotten out of the way fearing a rocket, and the game was over.
For me the most mysterious guy in Connecticut was Aramayo. He was terrific in Bridgeport and went to Hartford in his mid 30s. Most guys in jai alai don't decline that early, but Aramayo got old really fast.
I also don't remember Michelena at Hartford.