It's hard since shieldbots are naturally much tougher, spiders are designed to be more agile and skirmishy. Venoms (emp spiders) drain shields, use lots of them in combination with hermits or recluses, hermits are better for direct attack and heve more health, recluses are longer range and better if you have a big terrain advantage.

Also try using infiltrators to stun on felons then taking them out.

If they make a large shield you should be able to keep it drained without being in range of anything.