perfect reason why shields are OP as fuck. there only so little counters to shields mixed in with felon balls and racketeers WHICH lock on everything not to mention shoot so fast. then they got roach to blow everything up.

for starters, skuttles need a higher blast radius. Roaches beat it in every catagory. make 5 roaches, cloak them or just have them dig in and you get same result.

Try making snipers.

Because felons cost 10 metal, thugs 5, racketeers 6, and the rest is complimentary when you buy the factory.

Throw in some warriors / defenders to kill raiders and your fragile problem disappears as you can't damage what you can't see (obviously this requires a little micro in that you don't throw your warriors at the shield ball).

if you want, do penetrators/pillagers (+hammers if there are aspis)
penetrators/pillagers are awsome at destroying shieldballs from 1000+ range

Once there are several aspides snipers become ineffective. Cloaked roaches are an excellent counter to shieldballs as long as there isn't a bandit screen. The most important thing is to take advantage of the enemy's inability to split his forces by expanding and raiding as much as possible. As ddab said artillery as a good idea against any number of aspides to keep the felon's ammunition down.