I play marauder a lot. It's my favourite alien.
Teslas are hard to jump past. They have big knockback and are big themselves. They don't need to rotate, and start shooting you as soon as you get in range. In open areas, I hope to find turrets instead of teslas. Turrets spend a lot of time rotating. If you place them in T-shaped corridor (Tremor), a marauder can approach them from the other side, damage (zap is good for clusters), and run away. When I see turrets guarding a passage, I start to think how to outsmart them. If there are no humans around, I may brute force 2 turrets with a marauder, it takes some resting in between, but can be done. If I see teslas, I give up unless they're spread widely enough. Walls of turrets are more vulnerable to domino effect, too.
Marauder can be very harmful to a base. Last game, I jumped past 1 tesla and another one being built, ate armory, 2 spawns, and did some more damage.
I think a mixture of both is the best.