Ultimately, as always, well just have to see what happens, as we cant predict the future
Once you have a solid crewing engine on the battlefield, all your Vehicles can discount Urza for each one you control that's currently a creature, to get it onto the battlefield quicker
There's a chance for certain cards in the deck to have a special design
"Little did he know I was right behind him the whole time like a ninja," he quipped in his post
In short, you want to balance the mana value of your spells to ensure you have effective spells to cast throughout the game
It's one of the biggest divergences between the versions of the franchise, and ironically, it leaves the game even more unbalanced