Question:
If vaults where half the size and each player could use any 15 cards of their element even if not in the vault there could never be an illegal deck. Would this fix the balance and cause for suicide or simply remove tactical gameplay by giving them half a deck for free?
Both.
If teams are always able to have 15 cards of their own element, I doubt they will be any reason to field anything other than the best deck possible (the other half of the deck will eventually get weaker, which is fine). That itself would make for more interesting fights.
Additionally, what I find positive about this, is that elements without many different decent attackers ( for example), will be able to field more decks with their "best" creature.
Downsides are, suckish creatures probably wont be used at all. IE, didnt pack crappy Virus in the Vault, but if you give me 15 "free" cards every round, I wouldnt put Spiders in either; I'd take them only for decks with upped cards, or if I need Web, so you'll get Mummies running around all over the place.
About Vault building, having a good vault with those set of rules wont be any less important that it is now. Yes, fielding decks would be easier, but better designed Vault will still have advantage over poorly designed vault.
I'm afraid there will be too many people against this idea, so even if you find a few people supporting it, it will be extremely controversial. I guess it would be better to avoid it and try to find a solution that lies somewhere in the middle. (Also, bigger decks are once again discriminated)
That's why I would support possibility to convert cards into in-element cards other than pillars, with some set of rules limiting what can be converted into what, but with little limits on the number of cards converted. This would fix the ratio problems, salvaging would be always a good thing, and it would strengthen/allow mono decks to be played (right now they are often impossible to be made). On the downside, it would make intelligence harder and could make vault building a little less important, but that's where proper limits to 'what can be converted into what' comes to play.
For example, with the rules I've given earlier in this thread a deck like this:
4vl 4vl 4vl 4vl 55k 55k 55k 55k 55k 55k 55k 55k 55k 55l 55l 55l 55l 55l 55m 55m 55v 55v 55v 55v 55v 55v 576 576 576 576
Can be converted into only one possible set of Time decks:
5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rg 5rk 5rk 5rk 5rk 5rk 5rk 5rn 5ro 5ro 5ro 5ro 5rs 5rs 5rs 5rs 5rs 5rs
With reverse times interchangeable with precognitions, pharaohs interchangeable with anubises, and pillars interchangeable with pendulums.
As you can see, a very poor deck. Yet far better than a suicide. Yet, any deck that can counter Time well, will counter this deck even easier.
And as far as my suggested rules go, once you change a card into a Time card, you cannot change it into another Time card, even from the same category. Thus I think my suggested set of conversion rules wouldn't hurt intelligence that much, and vault building would be only slightly easier.
And yeah, this example is a bad one, since you would never convert a whole 'opposing element's deck' into your own, but rather off-element cards from your vault, but I simply wanted to show how poor decks result from this kind of conversion, so that people like QuantumT are not afraid of a sudden rush of mono decks breaking their intelligence apart.