New player tier list idea: best LD5 combos for account growth

I find it kind of strange that in all this time nobody really made a tier list focused on a brand new account. I get that in a lot of cases it does not matter much, because when something like Lucifer exists, he just takes the top spot in almost every pve ranking anyway.
But what if we look at it from a different angle: what about combinations of two ld 5* units, with the main focus on growing a new account? I mean not only pve, but also pvp and overall progression.

Which combinations do you think actually make the most sense and give the most value in that situation?

To me it feels like Lucifer is almost always one of them, but I am not sure who the best second ld 5* would be. I have a few ideas, but I cannot really decide which one is the strongest or most useful.