JiffyPopTart
Bree-Yark
Spikes in and of themselves can be a problem. If the game works on the assumption PCs are dealing around X damage per round and a character spikes 6X damage in a round it can make an interesting encounter fall flat.I don't think it is, people notice it because the spikes stand out but it seems to average out in the long run.
For numbers, I can only relay my experience from the Solasta video game which tracks damage per PC. In the game, the two weapon fighter generally does the most damage, paladins are second.
Do you think the actual smite spells listed would be balanced if they could be used without an action and without preplanning like the substituted damage smite could?