So in other words, you walked right into a colony, but didn't bother to look ahead to see that there were "like 300 spiders" to greet you? ESGs double for cockaroach hotels and raid is an additive in the acid clouds. Those bugs won't stand a chance. Also, try to keep a few lynx nearby to augment the Tigers that weren't knocked out. Unless you have more than 1 front, an EMP missle should -never- knock out all your vehicles.
Oh, yeah, there is a mobile meter defense for OP2. They're called EMPs.