Something that I have figured out is that without a backing band some of the "Right" strums make a song sound wrong.
Bingo!
That's why there is rarely "one true, correct" strum pattern for any given song. Quite simply, there's usually no uke in the song to begin with! You might as well ask what the trombone part is for "Back in Black".
And even when there is a uke, there are usually other instruments playing along with it, so if you just play the uke part by itself, you're missing a lot of what the song is doing.
So any solo ukulele strum pattern is really a
special arrangement of the song. It's an attempt to distill elements of the full-band version down to just you and the ukulele. After all, you can't play everything in the original version. You gotta make choices.
Ah, but which elements to you keep and which to you toss? What parts are the most important and/or interesting? Which elements do you change to better fit the new circumstance of the uke?
That's where judgement calls, artistic interpretation, taste, and your own playing ability come into play. And since these factors are different for everyone, the "correct" strum pattern will be different for everybody.
JJ