I've attempted to dig through the forums to see if there was any discussion on these two mods in particular. Found one 4 page thread relating to Ruins Clutter Improved, and while there was discussion about other mod conflicts, nothing about the enchanting candles. Leanwolf's SE version of the mod contains 6 meshes, including one for loading screen art.
Having downloaded the STEP Compilation for original skyrim and compared it to LeanWolf's Enchanting Candles (also downloaded the original Skyrim version), it appears that the only thing that Ruins Clutter Improved overwrites is the loading screen art, in particular "loadscreenenchantingworkbench.nif". For this reason, I'd suggest on the STEP SE list to list LeanWolf's mod after Ruins Clutter Improved (and perhaps make a note of it).
You mistake this list of mods as a guide. It's is not a guide. Currently, it should only be considered a list of STEP mods that have been converted to SSE; nothing more, nothing less. This is why I said in my previous reply that if you use this "list", you're going to have to guess as to the intention of how the mods are installed, ordered, etc.
I've provided a patch at the bottom only for those wanting a STEP-like install on SSE, but do not have the knowledge to make a conflict resolution patch of their own. Anyone using this patch should follow the directions given on the page. This patch is only for the plugins, and has nothing to do with the install order of the mods, though they are generally in the correct order bar a few as you have noticed. However, this will not hold true once we release STEP 3.0 as the structure of the guide will be changing.
But...as you can see from the number of missing mods, this list is far from being ready to be put into a guide format. I happen to be running this list of mods using WB right now. There are a few issues here and there, but it's mainly stable for those with the know-how to install the mods on their own. You seem to be able to do this, so I'll leave you to it. ::