Two generations of LHWs, actually
One of small LHWs who were also MWs or could have been MWs
And a bigger generation of LHWs... Gus, Santos, Smith, Glover, others... the guys who are actually 6.3 feet. DC is an exception.
But I wouldn't say he dominated this generation since he clearly lost to Reyes and his wins vs Gus and Santos could have easily been draws or either way.
But indeed, he dominated the small generation, those guys looked like Jones' smaller younger brothers.... Machinda, Rashad etc...
Michel Pereira has more muscle mass than Shogun
And many other examples
Today's fighters are just much bigger.
Frankie was small at BW