For some odd reason I thouyght only 300 rohirrim defended Helms Deep. Only 300 PE seems quite small now zin comparison, however I do think those three hundred would kill quite a few orcs. With about 100 archers, 10 fire beasts, 100 warriors, and 86 guardians, the PE would be far more professional and deadly in my opinion then the average warrior of Rohan. With
Elien, Fire Drake,
Laleya, and Malaena reinforcing weak parts in the line, the PE have a strong force. Their number s would be far to small to hold the walls securely. Their best chance to beat the orcs or atleast wait for gandalf would be prolonged hit and runs attacks. Have the archers thin out the numbers before they reach the wall, and then gradually pull them back. Use warriors to slow down orcs in the courtyard with their speed, with the archers prociding any covering fire.
Elien and his cadre of guardians should be the last line of defence, holding a chokepoint to keep the orcs bottled up. They'll kill many, but the lack of numbers will be their undoing.
But if it was 2500 PE, I honestly predict a slaughter. Long range archers, speedy offensive melee troops, well armored and precise defensive troops. Not to include 3 very capable champions and a summoner with some nasty offensive power