MTG Salvation

Between this and unbound flourishing, Rosheen Meanderer has some fun new toys to work with

This is an interesting card but I'm not sure the colors it's in would want it very often, compared with something blue and black for counter magic, draw, discard, and removal.

Green has a lot of recursion. Red has very little. Actually, come to think of it, until recently, red was probably the color which had the least mechanical overlap with green.

Well, it's "at random", which sucks, but at least you can just return every card in your graveyard because it's "X".

But my question is: how do you choose x random cards from your graveyard? I mean, i can't seriously find one.

You can't just shuffle it and chose the first X for 404.2: [...]A player can examine the cards in any graveyard at any time but normally can’t change their order. [...], and the cards itself doesn't explicitly tell you to do so.

Moreover, you wouldn't just flip it upside down and let the opponent choose since as you declare your casting he can ask to see your graveyard and see where relevant cards are.

So, which would be a correct/the best way to choose X random card?