Cloakie vs Amph is tough until you get phantoms.
All their units are just slightly better in almost every circumstance.

You can get 3 ronins for 1 buoy, but mass cannon fodder is just asking for limpet counter.

as cloak.... you can use cloak?
imps are strong defensive, sling is a cheap arty that beats amph until grizz, gremlin is great scout, scythe allows for stuff

slings cause passive attrition in a cost effective way. A few slings and you force the amph player to move around (apm), fall back (lose territory), or push (into static defenses?). Its annoying and hard to deal with unless the amph player has a large enough army advantage (then its gg) or slings have a wall behind them (why?).