Personally, I think that this adds unnecessary complication to minions. One of the main reasons to use minions is so that you don't need to track hp for them... by creating a stronger version of minions that have a relatively small number of hp, that advantage is completely negated.
Perhaps, instead of a numerical value for hp for these guys, just give them a bloodied state. So now, the first hit on the goon reduces it to bloodied (with all the mechanics that are included in that), and another hit kills it.