20 + 22 = 42.
Talaxians helped get Voyager back in Basics II.
That means that their trade routes were as extensive as the Kazons.
Empires are blob shaped, not circles or squares.
(Although I imagine Borg space to be a perfect sphere.)
Voyager was definitely passing borders, but lots of other aliens travel across borders too, that any species Voyager encountered in their own home space, other members of that same species could be found as a tourist, immigrant, trader or invader in any other neighbouring empire.