Pollywog and Slither's ward skills are severely weakened due to creeps and tower attackign wards over heroes and units. In DotA these wards have lowest atk priority so they are relatively safe, and their strength has been balanced for this. In HoN however they are attacked before creeps making both skills very weak due to the wards low hp. As such I would suggest either sorting out the priorities or buffing the wards, as these skills are incredibly weak. Especially for Pollywog as it's his ulti.