There's a way to make them more challenging, without making them overpowered. On 1 vs 1, humans always win in the long run. It gets different with small groups.
Take by example if Drifters appeared in groups of 3 that cooperate. Now add that there's 3 different types of Drifter ships.
One is the Artemis, a dps-focused battleship, second would be the Apollo, with the ability of remote logistics along with dps and third would be the Strategos, a Drifter that has command ship bonuses along with dps (with stackable command bonuses, for below idea).
Now if you make the groups of 3 be a random composition of these ships, you could get some interesting & challenging groups, from a triangle-repping Apollo trio, to a group of one of each. As you don't know what you face in advance without scouting ahead, you'll either need more flexible ships, or carry around a variety of modules & ships.
This would be enat, in combination with their 30 minute cycle they exhibit with their wormholes (they enter & leave roughly every 30 minutes, could be fun if it changes group composition every 30 minutes, giving players little time to prepare.