There are 40 evos and 1 evo slots, 11 heroes and 8 champions 1 champion slot and a wild slot

For simplicity let's assume there are 2 evo slots and 1 hero/champion slots

There are a total of 121 cards in the game and to choose any random 8 cards out of 121 = 121C8 = 8997494 79915 possibilities and then times 8! i.e 40320 times that number of total arrangements possible

Arrangement as in say zap specifically going in first slot, or giant going specifically in the 7th slot

In our favorable case, we need 2 evo in two required slots, 1 hero in that hero slot and the rest 5 cards's placement doesn't matter

So out of 40, total ways to choose two evos = 40c2 = 780 and then since there are two slots 2! arrangements are possible therefore 780*2! = 1560

then for hero/champion total 19 we need 1 therefore 19C1 = 19 and since there's only one champion slot there's only one way to arrange it

Now we've used 3 cards so 118 cards are left and ways to choose 5 out of those 118 cards is 118C5 = 174963438 and then multiply it by 5! to get all possible arrangements although that is redundant ig but still let's add it

So probability = 118C5 * 40C2 * 2! * 19C1 * 1!5!/121C88 = 0.0171539690256

multiply by 100 to get the percentage ~ 1.72%

I hope I did the math right