If only the Otter player wants the Otters, then the draft decks end up too similar to one another draft to draft and it lessens the long-term Limited playability of the set
Six mana may be a lot, but artifact decks often have ways to create a lot of it pretty easily

First, let's check out the original list: Coven Counters | Commander | Wizards of the Coast Commander (1) 1 Leinore, Autumn Sovereign Creatures (38) 1 Abzan Falconer 1 Ainok Bond-Kin 1 Angel of Glory's Rise 1 Avacyn's Pilgrim 1 Bastion Protector 1 Champion of Lambholt 1 Custodi Soulbinders 1 Dawnhart Wardens 1 Dearly Departed 1 Elite Scaleguard 1 Enduring Scalelord 1 Eternal Witness 1 Gyre Sage 1 Herald of War 1 Heronblade Elite 1 Heron's Grace Champion 1 Juniper Order Ranger 1 Kessig Cagebreakers 1 Knight of the White Orchid 1 Kurbis, Harvest Celebrant 1 Kyler, Sigardian Emissary 1 Mikaeus, the Lunarch 1 Moorland Rescuer 1 Odric, Master Tactician 1 Orzhov Advokist 1 Riders of Gavony 1 Sigarda, Heron's Grace 1 Sigarda's Vanguard 1 Sigardian Zealot 1 Somberwald Beastmaster 1 Somberwald Sage 1 Stalwart Pathlighter 1 Trostani's Summoner 1 Verdurous Gearhulk 1 Victory's Envoy 1 Wall of Mourning 1 Wild Beastmaster 1 Yavimaya Elder Instants (6) 1 Beast Within 1 Inspiring Call 1 Return to Dust 1 Ruinous Intrusion 1 Swords to Plowshares 1 Unbreakable Formation Sorceries (8) 1 Bestial Menace 1 Biogenic Upgrade 1 Celebrate the Harvest 1 Celestial Judgment 1 Cleansing Nova 1 Growth Spasm 1 Hour of Reckoning 1 Shamanic Revelation Enchantments (4) 1 Citadel Siege 1 Curse of Clinging Webs 1 Curse of Conformity 1 Death's Presence Artifacts (6) 1 Arcane Signet 1 Lifecrafter's Bestiary 1 Moonsilver Key 1 Sol Ring 1 Swiftfoot Boots 1 Talisman of Unty Right out of the gate, I'll admit I'm kind of baffled by this list

Its worth noting that extra combat effects arent the only way to take an extra combat
Brawl Not Legal Vintage Legal Timeless Legal Commander Legal Pauper Not Legal Oathbreaker Legal Penny Not Legal Toolbox Buy This Card Notes and Rules Information for Wizard Class: Each Class has five abilities
They were issued in 1998 as part of the CoroCoro Comic Illustration Contest