Extremely rare? This actually happens to me more than winning. Either my luck is very bad, or in over 400 games against the gods, something is amiss.
You have awful luck. I must have played 200 or so games. I don't know if it ever happened or even came close to happening. So that's 20 MINIMUM of everything during a game except for one element having <6, and often... you sure?
A bias? Towards what? Currently, I play a rainbow deck. I like it, it works, it has the ability to be changed and upgraded to provide more variety, but it's built for the Gods, so it's not going to be changed. I've no problem with rainbow decks. All I'm trying to point out is that compared to mono-element decks, rainbow require much more luck, and may not work as effectively as mono-element or dual-element decks (though, as of now, dual element decks have problems with getting quantum). Honestly, I'd prefer to use a dual-element deck, but that's beside the point. It's a personal preference, not a bias.
So you went for 'pvp is fair'. <-- that is not a personal preference, that's an objective statement. Your arguments are unconvincing.
Number of differnet element cards in deck --- Best choice for towers (regardless of viability)
mono --- reg towers
duo --- your mark as the minor element and most of the towers as the main element.
trio --- your mark minor, and splitting up all the towers exclusively to the other two elements ,
or 100% quantum towers, both about as effective.
4 or more --- 100% quantum towers
If that's doesn't scream out that something is wrong, maybe you love how things are now and now want them to change, AKA bias.