The spell Summon Horde summons minions equal to the number of creatures in your team that have the same class as the caster. The Strength in Numbers trait should theoretically increase the number of minions it tries to summon for each creature by 2, but the number of minion procs stay the same with or without Strength in Numbers.
I do understand that since the minions are random, there’s sometimes overlap and redundancy, but in the battle history I can clearly see how many times a minion was summoned. And the number stats the same with or without Strength in Numbers.
I’ve tried with 6 and 4 creatures in the team, in both cases the trait didn’t make a difference.
I’m using the Android version, v1.0.57