Halo is a modern first person shooter game. And modern first person shooters have controllers that you hold in your hand with levers that allow you to move the angle of perspective in both horizontal and vertical directions. The player can see up and down just as much as left and right. Halo is just as vertical in its game play as it is horizontal.
It isn't enough to just forge maps where you can look up or down, but to enable players to engage (aim and effectively deal damage to) their opponents at vertical angles. Vertical game play makes maps more interesting, and is a feature you need to strive to include into your map.
One of the challenges you will face as a forger is the impact that sprint presents. Sprint requires maps to be larger, and as a result you will need to stretch your structures further away from each other. While the vertical movement doesn't change much, the horizontal movement will. And this will impact the slope of vertical engagements, making them more horizontal than for maps that do not play to sprint.
As a result, Halo titles beginning with Reach have show cased maps that are larger horizontally, but not necessarily vertically. The angles of engagements have become a little less vertical. And the engagements have also become less vertical as well.
Vertical engagements are an endangered species.
A new design paradigm must be accepted where sprint is simply ignored. You will have to just not concern yourself with the depth that is lost due to sprint and forge your maps without concern for sprint or no sprint. Maps that are forged without sprint in mind should yield less clutter (Solace) due in large part to less horizontal distances between structures.
With structures closer together, vertical engagements should become more common place once again.
Ignore sprint and just make your maps smaller with more vertical engagements possible.