Caring about the mana value of spells is a theme that runs in opposition to traditional Spellslinger strategies that want to chain together cheap, low-cost, and efficient instant and sorcery spells, and consistent token generation gives the deck a more impactful board presence to fend off attacks
As for how this all relates to your commander, each colored mana symbol that appears on a card in your deck must also appear on your commander
Radiant, Serra Archangel isn't bad, or Ravos, Soultender for some graveyard recursion
The most famous example is the easy infinite Zirda has with either Basalt Monolith or Grim Monolith untapping a Monolith isnt a mana ability, it just happens to control how often we can use the attached mana ability
The grim-dark world of Warhammer 40,000 doesn't lend itself well to pure representations of morality, order, peace, and structure