Some newer Mercenaries like Robaran and Taii Wakeen offer unique abilities, but older Mercenaries may not be as competitive
Or you can alternate cost it for four to ramp a foe, then one to your hand - better than other four-mana options, you might make a friends or help someone dealing with the mana screw
Quick Answer Standard poker-size playing cards measure 2.5 3.5 inches (63.5 89 mm), while bridge-size playing cards are narrower at 2.25 3.5 inches (57 89 mm)
If you prefer to build an indestructible fortress with Darksteel Forge before using Bolass Citadel to fish out one of the many infinite combos (mana, mill, turns, damage, etc.) artifact decks are known for, you can absolutely do that too
Equipped creature gets +1/+1 for each counter on this Equipment
Essentially, the synergy from keeping a weaker set of two cards needs to overcome the raw power of keeping the two "best" cards to make this the correct thing to do