My plans have changed. Fighting the alpha broodmother with megatheirium that have only 12 and 13k health is impossible, unless I can find one heck of a saddle. I've sunk way too much into this project to bail out now, so I've decided to use them only for farming gamma, and maybe taking on beta when I'm ready. For alpha, rexes all the way, my great female breeder will make that not too bad. Or maybe spinos. That mastercraft saddle is tempting.
What I actually did today was pretty fun. I got another leveled on Carno Island for the eventual gamma fight, grabbed lots of loot, and started work on a mini-base. I knocked out a 145 argent that looked incredible, but it disappeared after I left and came back. I'm not upset, it would have taken a lot of luck for it to not get eaten.
Among the loot was an apprentice megatheirium saddle. Awesome! Pre-made, but still very good luck. To be honest, while the levels don't flood in as quick as the Swamp Cave, it's much more reliable to farm Carno Island. Tomorrow, I am totally flying in the rest of the army. I might bring my lystros too, they'll help any not actively getting leveled-up.
I also made a change with the way I'm leveling. My megatheirium can hit awesome melee before their health is in the target zone, so I decided to stop with the "one health, one melee" routine, when I reach the zone and go full health. This whole thing would have seemed so boring to me weeks ago, but it actually feels exciting now.