The tactic is to use a lobber to lob another lobber, and then lob your opponent into lava or water. This is sort of funny to do yourself, and is a nice use of physics in the game. But it is OP and I think it doesn't have a good counter.
It isn't much fun to play against, especially when its cloaked. Nothing much seems to reasonably counter it as the lobbers themselves are so cheap. Usually defences and units will miss the incoming lobber because of its arc (Stinger included). And the
instant it lands with even 1 HP it fires and your units are dead (big units or groups too). You can flea spam at the cloak, but it is not at the front of this and fairly easy to defend with light units or porc. Without lava or water this is less OP but you can still lob them into your waiting DPS units. I have no clude what the counter should be, especially for the stupidly low cost of doing this. Have I missed something?
Chaining lobs together is an OP force multiplier for your own slow units too, and sort of undermine the be strong or fast but not both idea in ZK.
You could make lobber only lob friendlies, or have a delay to fire after landing, or make lobbers unlobbable. However I get that its a fun use of the game's physics features. So maybe a better way to counter rather than a nerf would be good here?