Well now i am puzzled it almost looks like you answered your own question ?
There are 3 sorts of aoe effect though apart from growl what about furious
howl ?...
Gorillas do have a nice Thunderstomp but when on cooldown just become another pain in the *** tank pet with low dps not high dps +2 does make a little difference i agree though , and their food requirements are also not helpful..
I tried a gorilla and as it has no fast attack decided that thunderstomp plus the cooldown was not for me...
The bats/owls/carrion birds do have screech and all have dive , But depending on play style can either make targeting a mob slightly harder or annoy a group you are with by using screech and the flapping wings ...
I have tried all three and saw little difference overall in damage or health , But screech does seem to create a bit more threat so are worth having...
The missing aoe Furious Howl for wolves can be good depending on your view of it , I agree it needs scaling better , But a little extra damage from party members must help a little , But as bite has a cooldown i guess they do have lower dps...
The Dragonhawks are good but the same comments about the flapping wings as all flying beasts rule for me there , i tried one and yes the firebreath is good as i have a reasonable attack power it worked quite well but that is a forward cone as others said so not aoe effect...
There is also Wind Serpents and many love them for the Lightning Breath , Not aoe i agree but both the dragonhawk and the Wind Serpent can be by your side and still attack any mob within reach by your clicking their attack spell , i tried both and they can do a lot of damage , and if you forget about training bite do seem to stay at distance and take less damage out of the two though lightning breath and the Windserpents rule as it is a focus dump and they get +7% extra dps..
My favourites with flying beasts are the Owls and the Wind Serpents both are worth having for their DPS...
AS has been said Ravagers do great damage and seem to need less healing than most pets , but not my favourite pet as i kept one for about 5 levels and got bored with it..
Most pets if sent into a group of up to around three or four seem to switch there attacks between each mob from my experience anyway , So will have a sort of aoe effect on the group , The trick is to use a threat meter and adjust your shots or even stop your attack for a few seconds so the pet keeps the mob under control...
The real answer is pick a pet you like the looks of and can tolerate its habits , I have tried every pet family so far including castor pets , every single one did its job and i agree some need more healing or do less damage than others , All are worth having..
Until they reset each pet family with its own Special family attack there is so little real difference in the pets anyway...