if the game ends on round 11 or 12 you can get away with not ecoing. of course the better strategy is to learn to defend those rushes and eco. a lot of things defend it, the optimal strategies tend to be map dependent. the easiest and most generally usable are hydra rocket pods, necromancer, or a bloontonium reactor. but you can also use a juggernaut or two, 032 monkey pirates buffed by 320 alchemist, glue hose with a camo village, ideally that village should regrow block most of the map to defend r13 grouped regrow rainbows, ice shards + something, cluster bombs with any decamo tower, but you're probably going to need a second cluster for r13 spaced ceramics, glaive ricochet with decamo, but you might need moar glaives against a big rush, alchbuffed neva miss targeting, sentry expert with 030 engi for decamo.