With new anti-cav items ranged could have some protection against cavalry on flat ground and hopefully ladders could be removed from the battle modes.
These spike walls would be easy to get over by being infantry, so these would only give protection against cavalry.
Maybe 1-3 slot items.
Note: The spike walls does not need to do damage. It is there to stop cavalry charge and provide certain protection from cavalry from specific direction.
Also the spike groups, would propably best to do from single spikes (as in pic #2), as the spike_group props might be a too tight to get over by foot.