this is a good food for thought article.
consider a toolbox deck which has a lot of 1-ofs and tutors. you say the chances of drawing a 4-of is only 0.1% less. let's assume that you're right. so the chances of drawing a tutor remains about the same. what if you add an extra 1-of that can be searched by the tutor. that extra can be valuable, while only minimally affecting a bad opening hand. thoughts?
Ire of Kaminari - 3R
Instant - Arcane
Ire of Kaminari deals 1 damage to target creature or player for each Arcane card in your graveyard.
#109
looks like a bomb in Oath. you don't even need 20 arcanes in your deck. about 12 or so is enough if you can cast this twice.
hypothetical turns:
upkeep, oath triggers, everything including 21 arcane cards goes to GY. flashback krosan reclamation for timewalk and ire. main phase, cast timewalk.
next turn, untap. draw and play ire. you win.
if you got 12 arcane spells in deck, then reclaim two ires. win in 2 turns. i'm guessing 3rd turn wins are possible.
okay not exactly meandeck oath, but looks good in budget oath.