On one hand I agree, on the other hand I'm most of the time watching him and just thinking "nice, but normally WR's are about going to the human limits, where here it mostly feels like holding back for the financial bonus"
Don't get me wrong, that is not in any way negative about him, because he is absolutely 100% right in doing it this way in the only event in which that is somewhat feasible It just feels a bit less like something amazing when you know the WR is not even the current limit, as opposed to for example running, throwing or long jumping. If you know what I mean, I realize it's hard to put exactly into words without sounding negative (which, again, I am not ).
I'm also not too familiar with him. Don't think he's ever competed for Slovakia internationally. My guess is he's an American of Slovakian descent. Perhaps he recently decided to compete for Slovakia? He was competing at the US Olympic Trials but he's listed as the Slovakian record holder on Wikipedia and the Swimrankings site. It could also just be a mistake and he intends to represent the US.
Swimrankings - PERECINSKY, Martin
Brazil doesn't have any entries. There's also Sweden that doesn't have any entries but they're better on the women's side (although they don't have any women in the top 10 either).
Australia with only two entries also feels pretty low for them.