I just had a test game of AoS where I used my jungle swarms for the first time (1 unit with 4 models) I was playing against chaos warriors with a bloodthirster at the front so I charged it with my swarms (because, why not)...and the things nearly wrecked the bloodthirster! To be fair he had a lot of bad luck with the dice rolls, but I really wasn't expecting that many mortal wounds.