There are some really good pilots who live in different time zones and can't be online every time you are there.
As a matter of fact, I'm flying in the same time zone as most of the guys you mentioned, but, since late beta, I can only recall 2 fights against Hangtime, once I seen Hristo and maybe I have seen Wardog up. Others, including you, I might have heard of, but have never seen either of you up.
Main arena, no matter how small it looks, is huge. That guy might be flying to fields that are not most active and that's how he picks up his kills.
The only time you'll know for sure that someone is indeed using multiple accounts, is when they will tell it to you themselves. Until then, it's nothing more then your assumption.
mx22