sure it is if you don't attack the weaker erebus. attack the erebus not the minions. an hob minion erebus at the lavel we are talking about ahs no chance against any other demigod.
hence as i said the only problem is that the erebus can be miles away from his minions.
the item is totally useless if a demigod can protect the tower by destroying the minoins because there is ALLWAYS a protecting demigod. i would never take this item again if i cannot do really heavy dmg, nearly destroying the tower even though an opponent is sitting next to the tower. this is allways the case.
considering what i have to give up for this tool it seems worthless to me. for the rare situations i can attack a totally unprotected tower it wuold not be worth taking HoB over BotF.
but again, it is yet to be seen if this change really allows you to kill the minions fast enough.
edit: obviously it is a question! and i am not the only one wondering why HoB in the current status is called op.