Ulrezaj consisted originally of three Dark Templar, but now is made up of at least seven.
This makes me wonder whether that's a simple retcon or if an archon can merge with additional Templar after their original merging.
That leads into the second point. Archons have a limited lifespan (though we know not how limited). I wonder if merging additional Protoss into an existing archon can extend its lifespan by absorbing additional Protoss.
If anyone knows whether this is the case, or if it even makes sense, your input would be appreciated.