Is there a way to reorder mastery pages without deleting and readding all the masteries in? Bit of a trivial thing, but I like the aesthetics of having, say, all my solo top mastery pages in one place or likewise with my jungle mastery pages etc etc

No, there isn't.

Please for the love of all that is good Riot let us click and drag rearrange our mastery and rune pages.

bump. I would really like it for Riot to implement something like this. Sick of my mastery pages being out of order.

^ mhm