Reinforcement of the Army can make sure you have the warrior you need, and King of the Swamp or Fusion Sage can make sure you have access to Polymerization
What this does well is add some redundancy to any deck with green, that is able to get to four mana and wants to "Show and Tell" more often
My favorites of these cards are Cecil, Dark Knight / Cecil, Redeemed Paladin, Tonberry, Dragon Sniper, Vampire of the Dire Moon, Ashnod, Flesh Mechanist, and Tinybones, the Pickpocket
There are a lot of assumptions here, and Im sure real statisticians are looking at this and wincing, but the point I mostly want to make with these charts is the following: If something has a 1/100 chance of occurring, and you do it 100 times, theres no guarantee of getting that 1/100 chance odds
It is seldom correct to do this, but much more often than in a Constructed format
They have resources that we do not and cannot know about