The algorithm takes into account past war performance. As a new alliance, your war performance will be blank for a while & as a result not be factored into the algorithm. You should find you start getting linked to more evenly matched alliances soon.
Guvnor hit the nail on the head. War record history is the one factor that can be exploited. Ive been a vocal “complainer” of it, but the more we all talked about it the more of a pain and time intensive work it would take to continually pull it off. Easier just to buy offers for ascension mats than an alliance to do this.