Only stats affect combos? (some info inside)

Hey everyone. I've been doing some testing and it looks like to me that when making a combo, only the damage and health stats on the cards matter. (the Hammer and Heart icons on bottom-right)

You can see this if you have two cards that combo with the same card, that the higher stat one makes a higher stat combo with more abilities. But what I noticed was that secondary abilities in that cards you combo FROM don't seem to matter at all.

As a sidenote, this means if you have a well upgraded/statted common, it can actually be better than a rare. Once you get better cards you can recycle them for 96% of their energy back too. Not a bad investement. But obviously just fuse cards you use a lot, like beer or pantry guns.

Anyway, what I would like to ask the rest of the sub is can anyone confirm and agree with my theory? It might seem like an obvious question to some, but it'd be nice knowing this for 100% sure for future upgrades.

As a bonus for reading this, allow me to share some info on the best statted green/rare cards to use in your combos. This only includes categories where there are multiple rare cards, like cars. No point talkin about something like music cards when Bluegrass is the only rare.

Out of all the car cards, Food Truck is clearly the best statswise, and as far as I know there are no epic or legendary land vehicle-type cards. Since it is the best card in it's category, I recommend at least farming few copies of it. 2-2 works well. SUV has second best stats, Red Ford Truck is a -2 atk weaker.

As far as the two restaurants go, Pizza Overlord beats Elzar's Fine Cousine without fusing, and after fusing once they tie. The difference is +2 atk and -2 hp. You could use both if you fuse at least once, otherwise stick to Pizza Overlord for a better Beefsquatch.

Finally the 3 school-type cards. Mars University and Pearl Bailey High School tie in total stats without fusing, but PBHS has +1 on both stats over MU after fusing and upgrading. So if you are farming school cards (like for Billdozer), farm PBHS instead of Mars U. Wagstaff School has the worst stats out of the three, even after fusing. I would not recomend farming/upgrading it. Also if I'm not mistaken, there are no blue/epic quality school cards. There is a legendary one but that one can't be farmed, so you might want to farm some copies of PBHS while you get those American Dad epics farmed.

Edit: For anyone reading this later on, it seems that SUV actually has ties with food truck on stats after fusing, and it has more attack power which means more frenzy and other abilities. So SUV is actually better than Food Truck. My bad there!