I'm not sure if this is still a thing, but I remember that another way to aquire heroes was throughout the plant or zombie missions(the 200 per side at top of home page)
It was almost a year ago and my memory for some things is great, but others...not so much. But I remember that after a certain amount of levels you are given an option of two heroes that share a trait. And if I recall correctly, I was able to get a hero for at least each trait, not just 3 guys either, like I don't know if it's still that way, because I hear lots of people on forums that only have a few.... I will bring it up in general and find out what is what
As far as the different packs, your best bet is to go to collection and then search each keyword. Premium, Galactic, and Colossal. You can also do same for Event to see only the event cards, rather than trying to scour the screen up and down to find one.
And searching the sets like this will give you a better idea of what you think you want to try.
The hero specific packs are a tough one. They are double the price as a regular set pack, and you still have the same chance of getting five uncommons and a rare. There is no "bonus luck" for these and I personally don't like them at all. The obvious upside is you control slightly the cards you are getting, but if you have majority of that heroes cards, it starts to become double gems for recycled cards( being the cards after 4 of anything is recycled) some people save them for reasons that I don't know, because after four they are useless. May as well get something for them, unfortunately the rate is 25% of cost to craft. You see that when you look at a card. Price to craft and price to recycle. So a legendary that you have four of already becomes basically a superrare in trade, because you get 1000 to recycle the legendary, and thats the same cost to craft a superrare and most event cards.
Sorry for the rambling on, but I don't even realize that I do it until I reread
