I doubt that the game designers would permit the player to personalize Spartans. As was mentioned several times, the trailer for Halo Wars revealed Spartan group OMEGA, meaning that the UNSC will have a few Spartans at their disposal. In an ideal game, these Spartans would be equipped with Spartan Lasers. (It would be both appropriate and suitable for them) However, as far as we are aware, Spartan lasers are experimental weapons that were not introduced until the year 2553. Ensemble would have to modify the Halo plot in order to introduce Spartan Lasers at least twenty years in advance of Halo's discovery. While such a modification would be well within their authority to introduce, I suspect that it would leave many players confused with the precise contiguity of the timeline.
Lasers notwithstanding, I expect that we will be able to equip the Spartans with a variety of weapons, similiar to Dawn of War. Rocket Launchers, Sniper Rifles, and Assault Rifles are all viable weapons. Perhaps the Spartans can utilize anti-tank mines, to supplement their combat prowess. In terms of their battlefield application, Spartans would function in the capacity of a specialist assault force, designed to penetrate enemy lines at a critical junction and force the enemy offensive to buckle. They could supplement ground troops as heavy infrantry (although, such a capacity is more suitable for a Spartan equipped with MJOLNIR Mk. V) or, perhaps, as a mobile raiding force. Harrasment and offensive tactics are the Spartan's forte, and I expect to see unique applications for them.
It is my hope that the next Halo Wars game will take place at around approximately the same time that Sigma Octanus is invaded, since the Spartan III's were operational by that date. Considering that Spartan IIs are an extremely rare unit within the UNSC Navy, a game that takes place around the year 2552 or earlier would allow the player to deploy larger numbers of Spartans without compromising the integrity of the plot or timeline. Spartan IIIs, with their active camouflage equipment and superior biological augmentations, would be ideal for covert guerilla operations and other subtle warfare tactics, more so than the Spartan IIs with their inferior MJOLNIR Mk. IV armor. As it is, the OMEGA Spartans have no camouflage, no shielding, inferior augmentations, less modern equipment, and comparable training at best. I hope that Ensemble portrays the power of such Spartans realistically, rather than imbuing them with too much potency on the battlefield.
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