The skill part of this minigame is VERY minor, the randomness of getting even just half the number combos to line up right is just chance. Need higher player skill and less just roll the dice.
I don't think randomness is a big deal.
There's a good deck available for 15k early in the game, with bigger buffer size.
Then, if you manage to combine all the daemons into one (the end of one is the start of the other one), you have a very high chance of sending all of them.
In fact, I don't think codes are random -- it happens very rarely that I can't send all the daemons offered. Plus, the timer starts working only after you've pressed the first button. If you plan your "route" down the grids in advance, no problem at all.
And then, of course, there are legendary decks -- but that one is as easy as cheating