My submission:
1500 list for competitionPlan A: deploy all the infantry inside transports. Put the Farseer in the middle with the Spears, surrounded by the tanks. Everybody moves together to focus on one flank. The Spears can move up front, along with the Wraithguard and Scorpions. Avengers hang back, using range to effect. Serpents absorb overwatch, followed by Wraithguard, then the Spears and Scorpions to tie up enemy units. Spears and Wraithguard can both fall back and shoot next turn if it's more convenient. Follows the basic Eldar plan of using mobility and firepower to surround and consume.
Plan B: The Scorpions can deep strike if appropriate, the infantry can be deployed on foot as necessary.
Thanks!