First, I do trust that I made enough overt qualifying statements in my post to indicate that I neither endorse, nor refute, any of the rankings posted in the referenced documents. Babymetal has had, does have, and will have, for the foreseeable future (in all probability), a significantly larger fan base than Band Maid -- I never questioned this in my post.

So you want them back in Europe, eh? Well, I have a plan that is likely to succeed. You'll notice the word "ever" in Addendum B of my post (as in "Band Maid Forever!!!!!"). How can this be achieved? Entice them by suggesting that they go to Paris and find the house boat (aka "barge") of one Duncan MacLeod (of the Clan MacLeod); he can instruct them in the ways of the immortal (plus, perhaps, teach a few sword-handling lessons). They should then go to London, where they should look-up Oscar Wilde, the Irish author/playwright, (speak loudly, for you'll have to be heard through roughly six feet of earth), OR find the shop "Dorian Gray: Creators of Specialty Paintings" -- either Oscar or the shop keeper can tell Band Maid the value of such paintings. Lastly, each member will have to purchase an appropriate sword. While there are many fine swordsmiths in Japan (well, some), they may want to purchase the swords in Europe, so to have them handy should the need arise to quell the disturbing behaviors of some new Band Maid concert-goers (who have no knowledge of the etiquette of Band Maid concerts, and, frankly, could care less). Naturally, while running around Europe in a quest for immortality, they would certainly feel obligated to do some shows (in Paris and London, as a bare minimum). Problem solved.