Offensive: The Hastatus Squad is more powerful than the Hastatus Prime and with the fact that that the cost is quite low cost it is a great unit to spam against tanks, recons and artillery because of the high damage. Recon units can kill them especailly Epic ones that can plow through them without breaking a sweat so watch out for Zades and keep some fodder out in front. These are tough even for UR's to kill but they are a lot more vulnerable than other Epic units so be sure to support them especially with AA units.
Defensive: Railgun units are a lot less effective against recon so use any recon with an anti infantry cannon though beware these still have long range and will get 3 shots before your recon can close so something with good range or high health is recommended. Though these aren't as powerful as other Epic units they still are a pain for anything less than Epic to deal with. A maxed squad can kill a max Fumigator before it gets a shot off. Use infantry killers with support as each of these can take a few shots to kill. Helicopters can't be targeted by them and some really long range artillery can kill them in one shot. The Scheherazade I spells doom for these units and can plow through several squads.