One might argue that this is a "win more" card but given how much Marath wants you to have lots of mana, I think it's worth including
Stalwart Shield-Bearers As with each theme, one should expect a lord for it, and in defenders case, Stalwart Shield-Bearers acts as a primary example to buff all your defenders
Jhoira doesn't care just about artifacts but all historic cards, and some people don't like that because they feel she should just be about artifacts
That means youre purchasing from the secondary market and supporting scalpers
Plus, its restricted in Vintage
Teysa Karlov creates double the value for your creatures dying, and commands this deck full of ways to sacrifice creatures with great triggers - especially those that generate creature tokens for Teysa to give vigilance and lifelink with her secondary ability