how can I update an Oasis level?

Wow.. this is really getting complicated.!! (or interesting if you prefer) to get an oasis, after calculating all the above. I need to decide if all this is worth 100 iron/hour. ie I need to calculate the worth of loosing x number of cats!!? against the benefit!
...I did some scouting and found most oasis'es have many troops on hand..(they didn't seem to go hunting!?!? as noted above.) Krazy things in this game.. Many mysteries.. like why would ANYONE sell a lvl 3 ring on the market for 3000 coins!?! when the NPC will buy it immediately with no commission taken out..!!?

the number in all the oasis''es above are in white.. which I assume means not owned.. I think red.. means owned.. Soooo why would there be troops guarding an oasis they aren't collecting on???

Ok, it only takes 2 cats to take a lvl 1 oasis, so not sure how you are taking losses

White means nobody owns, but there is an NPC army in there that you have to beat to get the oasis