Often these creatures have abilities (banding, first strike, vigilance) that make the whole group stronger
Toploaders or penny sleeves can be great options for these cards
As a reprint of those sets, Legendary Collection also has some incredibly valuable cards, Dark Blastoise being the second most valuable reverse holo in the set
At minimum, when Lumra enters the battlefield, youre likely to get at least a couple lands into play from your graveyard after milling four cards
You get to cast that spell for free, which is incredible given the power of legendary creatures available to you in Commander
On the other hand, Yawgmoth, Thran Physician likely won't be as good in Historic as it is in Modern because we don't have undying creatures like Geralf's Messenger and Strangleroot Geist to combo with it