Well that just gives more time for your gaunts to get there. 32 hormies have 96 attacks on the charge (assuming you can get all of them within 2"), half hit, 48, depending who your playing against, let's say SM, about 20 wound, and about 7 die. One hole tactical squad down the drain, and sweeping advance.
Everything is expendible in a Tyranid swarm. If one thing gets blown to smitherins, just say to yourself, "It's alright, because I never liked them anyways!"
Seriously, they will either take away from the main fire power, or not get shot at, at all and will kill many squads before the enemy realizes that they are worth shooting, and then they will be over run by guants. They just can't win!!!
MUHAHAHAHAHAHA!!!!!