.... You can name the Hero Sets whatever you want as long as they meet the character limit (ie: "Cav Off" , "Invaders" , "Onslaught")
... AND there are equipment sets geared towards different bonuses. However if you really need marching speed on every set, you can put 1 Legendary Increased Marching Speed Gem in each item slot (IDK what the boost total would be because I found it rather useless, but you can do it...)