Id like to see an 'Armory' that has weapons and armor available to equip your troops with. These are similar to races but can be combined with them. They are purchased and require a certain level to unlock. basically these are better technology from building up your empire (account). Some have tradeoffs, like less attack or mobility.
Leather Armor: +1% defense, needs level 1
Chainmail: +2% defense, needs level 3
Scalemail: +3% defense, needs level 5
Platemail: +4% defense, needs level 10, -5% spawn
Body Armor: +5% defense, needs level 15
Short Swords: +1% attack, lvl 1
Long Swords: +3% attack, lvl 3
Polearms: +3% attack, strike first, lvl 5
Crossbows: +5% attack, strike first, lvl 10, -5% spawn
Rifles: +5% attack, strike first, lvl 15
Leeches: +1% Spawn, lvl 1
Tourniquet, +2% spawn, lvl 3
Splints, +3% spawn, lvl 5
Antibiotics, +5% spawn, -5% attack, lvl 10
Medikits: +5% spawn, lvl 15
either only gives a max of +5% and take awhile to get, but let you customize your army even further. each follows a progression to level 10 that has a good bonus with a small tradeoff. Level 15 gives the same with no penalty. Other options might work but its a good premise to start with. start with a strong race, equip it with good gear to get the play style you want, ultimately very high level players will have a strong advantage further encouraging strong players to play strong players.