Need Ideas on Map theme

Ok im making a spawning map that works kinda like "castle fight"
Except i wont be of course ripping everything straight.
Ive made the triggers, terrain everything... except units.

I just need feedback. What should the theme of the map be?

Ive got two main ideas which i cant decide on.

1) A mercenary/millitary style theme.
Pros - Wc3 has lots of weapon wielding units that could easily pass as soldiers, Also looks great with the terrain.

Cons - Hard to make trolls, orcs and humans fit well on a single race.

2) A creatue swarm theme.
Pros - lumping lots of creeps with a simmilar colour theme looks good, also a creep race wont raise eyebrows if Z is on the same team as X etc.

Cons - Looks bad agaisnt the current terrain.

Make a singular race for all players that is morphed one way or another, so generally no two armies will be the same.

For theme, maybe something random like

Orcs + Night Elves (greenskin melee, purpleskin ranged)
Dwarves + Goblins (pure 'plosives, goblin shredder for melee unit)
Felguards + Fel Orcs (red red red!)
Draenei + Dark Trolls (They kinda fit together nicely)