Hi there, sorry if there are grammar mistakes not a native english speaker.
They are valid, but I woundn't recommend the archers or silver helms at all! Just use 1 unit of 10 spearmen for blocking charges or holding backdoor objectives.
Sadly elves (High, Dark and Wood) from original warhammer kinda suck right now, except for the monsters, they can really pack a punch specially the frostheart phoenix and the dragonlord.
I would recomend to you, because elves count as order grand alliance, combining several units from other factions to reinforce yourself.
Now units from the high elves that are pretty good:
-Dragonlord (give him the Ethereal amulet from Shyish for a 4+ rerollable invulnerable save)
-Dragon princes (only with the Dragonlord battallion) 750 points for first turn charges is pretty sweet
-Anointed on Frostheart Phoenix
-30 man squad of Phoenix Guard (paired with the frostheart phoenix becomes a really anoying tarpit that hits hard)
-Reavers (great for grabing objectives)
-Archmage on horse (extra mobility for the same points)
-10 man unit of white lions are decent
-10 man unit of spearmen
Finally units that synergize very well with high elves:
-Namarti Thralls (excellent battleline unit that packs a nasty punch, but be careful because they die super fast)
-Glade Guard (battleline that can shoot decently and once per battle has a -3 rend attack)
-Doomfire Warlocks (good objective grabbers with meh shooting and somewhat good melee, but has a nasty spell)
-Evocators (Excellent anti blob units that hit really hard)
-Sequitors (A unit that buffs itself with reroll to hit to save)
-Knight Incantor (The auto dispell scroll is really nice)
-Arkanaut company (only with light skyhooks, awesome weapons with great range that can make tons of damage)
-Bastiladon (A living tank of doom)
-Dark elves Sorceress on foot (has a great debuff spell)
-Morathi (A half serpent demigod that can only suffer 3 wounds per turn, nuff said)
-Treemen (Cheap monsters that hit hard)
Thats what I can recommend. I would wait to see what happens to the high elves, becaues we don't even have General's Handbook Allaignance Abilities, but there's light in the horizon. Teclis has been referenced A LOT recently and with the release of Slaanesh I bet a true high elves or combined elf release is coming within a year or year and a half at most. Just hold in there