The guy in black is most likely closer to 4.5 than 4.0. The guy in white would have a winning record at 4.0, simply due to his skill in match play and pretty good movement. Great choice of shots, plays percentages really well has good court positioning...etc. He doesn't look pretty but he sure is effective.
Effin' lol at a 60+ years old 3.0 thinking he hits harder than the guys in the OP. Yeh...maybe on the one shot in ten that actually makes it into court. These guys have solid pace (especially the one in black). The other guy is the "crafty/redirect pace" type of guy but he hits a pretty solid ball anyway.
People thinking these guys are 3.5's are smoking crack or try to feel better about themselves on the internet.