that's not a bad idea for amphs to give them that
i just thought of new units for amphs and hovers. they also need animal unit types.
for instance i thought about a mantaray for the hover same size of mace and it fire mine but land mines that do the same like claymore. claymore is effective in sea. think of manta ray hover unit. looks like a manta ray and fires 3 mines and are magneticly atraccted to metal.
another animal is a strider unit like kraken but fast in sea but slow on land. walks with 4 legs and attacks with 8 legs. the legs get cut off and get extra metalf rom them.