If you want to know the consequences of you suggestion, look at WC3. They did multiple balance changes, but boosted 2 units so much (KotG, Ballista), that they destroyed the whole meta that was in place for like 10 years. It didn't add fun variety, but killed many strategies instead (to stay with battleforge, imagine a t1 unit gets so good, that it would make no sense to even go for t2 or t3 anymore). BUT, you could achieve something similiar by nerfing, which is less fragile (the worst thing that could happen, is that the card vanishes. You could destroy 1 race/element, but at least the other