The first pony for Twilight’s Royal Guard, partly based on my favourite IG unit of all times, the Rough Riders.
 
Not 100% sure, if I’ll stick with the armour design, but I like how the helmet has turned out anyway.  
The current plan is to have at least two units for every species.  
So far I got:  
Pikes: Earth ponies with pikes, strictly defensive  
Linebreakers: Earth ponies with claymores  
Line Ponies: Unicorns with muskets  
Pistoliers: Unicorns with tons of pistols (not sure about this one)  
Royal Lacers: See above  
Dragoons: Pegasi with either blunderbusses or multibarreled muskets
 
Plus some attilery (probably just gonna rip off the Warhammer Fantasy Empire) and some elite units/heroes (Wonderbolts for once).