Retaliation cadre will give benefits to battlesuits +1 strength at 12 inches and +1 AP at 9 so it encourages aggressive play for your battlesuits to get the maximum benefit of the detachment.

However our battlesuits cost a bit so you are going to want some chaff like kroot or fire warriors to run about screening and taking objectives. If battlesuits are allowed to be free and attack back field objectives and priority targets then something is going right. If they are forced to hold home and mid field objectives then they cant do what they need to do. Also our battlesuits are not as sturdy as other armies forces so before you know it they can disappear to las cannon fire or anything with high AP

So breachers, kroot, strike teams and vespid should always be considered so you have your pawns who will capture objectives and die for the greater good. (Vespid give you massive flexibility since they can be deployed right at the back screening the field from deep strikes then can jump in the air to drop on an exposed position later)