To Shawn Marion's stance... personally, i felt the Heatles more-so changed the game with small ball, indireclty. Ultimately small-ball itself was never desirable, it was more-so about having optimal spacing to run your offense (which MIA needed for Wade & Bron to succeed). But there weren't many big men available with that skillset, so you had to roll the dice with small ball as the compromise... putting a 3&D sf at pf and hoping you didn't get killed on the glass too badly.
But of course the need for optimal spacing and the apparent skill gap with bigs, led to more and more big men adding a serviceable or better 3 point shot to their game, to where most of the elite teams can at least have 4 shooters out there without compromising size/rebounds.