Tysons probably the best example. Despite being a small guy in a big mans division, he regularly came out on top. And despite being undersized, even in his losses, he reached the chins of the guys who beat him.
I think some of those listed were actually 'Educated Pressure' fighters when i think of a swarmer i tend to think of a Frank'Animal' Fletcher James 'Superman' Scott types.. I seem to remember a jr welter of a few years ago who was a saturation swarmer Jaun Venazula ?? or somesuch. Perhaps Sawn Porter qualifies ?
I don't see Lewis or Wlad as swarmers...seems laughable to even suggest those names ? Typical ones that come to mind are Tyson and Ricky Hatton..despite how highly you may or may not rate him he was a swarmer...ask Kostya Tszyu
Pacquiao. You couldn't get the guy off you. He was a bee that would just swarm, sting and then back off to catch his breath.