Well, let me share with you what my tribe and my alliance on Ark did when we were having an issue with finding a server to call our own.
We were very small, probably 10 guys max. Mind you that the mega tribes controlling these servers often have upwards of 500 players, all cycling time zones so a lot of people will be online farming and/or defending at any given time. So we can't surprise them. So we decided to just annoy the shit out of them. Flame arrows, random C4 on their farming dinos we caught out while they were farming etc. All the while living out of a 1x1x1 in the forest where they can't find us. Eventually they got so annoyed with us they started asking for help finding us. This gained attention from their enemies, who also contacted us. This worked in our favor, and we gave their enemies info on the server, they came and wiped them for us.
Of course we can't hold a server with a small group, but at least we were able to build up and play peacefully for a while.
My point here is that you don't have to be big to be a big name in PvP. Yes, it helps. But if you're good enough at guerrilla pvp and hiding, then you'll do fine. And if a group is being dicks to you, know they're also being dicks to other people in the area, most likely other small companies. So band up with them, ally up, and go get rid of them. A great place to do this is lawless. Also, if you do find a strong alliance, just take an island in lawless until you're all strong enough to go together to go conquest some territory in claimable land. It's not hard, it just takes patience, skill, and a bit of smarts.