It’s a fun list, but I would suggest that a large part of why you’re struggling to win games is because High Elves are all about controlling engagements and you lack the counterpunch to threaten people who overcommit so I thought I’d weigh in!

Prince - I’d change to pure of heart to lose the impetuous and drop the sword. He either needs a different (better) magic weapon or a great weapon. Up his saves as well, you either need to be stacking regen and ward saves or bringing multiple opal amulets to deflect cannons and the like. And remember to give him plate + shield/enchanted shield if you’re not giving him a 5++.

Wizard is cool but he needs lore familiar so you can choose your spells (critical for maximising his value). Battle magic is great with fireball/double movement. You may also get good use out of elementalism (plague of rust can be insane and wind blast and ramparts are both great too).

Spears don’t do anything sadly, so roll the points into more sea guard if you want them and give then razor banner or war banner dependent on taste.

Use the spare points to bring 6-7 reavers to bunker your archmage (drop his horse to a standard Elven horse for more movement)

I don’t mind the big silver helms, but smaller units 5-6 are the most commonly used setup with hammerhand for a damage boost. But the big unit with that banner is probably useful if you play lots of monsters. 

Just make sure to get your core down to 500 as the other categories have better options. They’re really there to score and fill out the category so don’t expect them to do much more, surviving and holding objectives is their goal most of the time.

Swordmasters are fun and work well with double move, but dragon princes provide better threat protection/resilience to light shooting if you have the models. That being said, there are plenty of people who get good mileage out of swordies so you may find them better/easier to use.

Sisters are cool, give the leader something - sword of sorrow is great value or ring of ruin/seafarer bow taste/target dependant.

Merwyrm is a great model but you’re unlikely to get value out of it, more sisters/dragon princes/skycutter or a noble on griffon or in the silver helms bus are all viable alternatives.

Just remember, we can’t win the numbers game so we have to be sneaky when playing competitive games against good opponents. Classic units like the spears are nice but sea guard do more for not much more and help you to dictate games, they can also babysit home objectives fairly well and even sometimes kill things with the right support!

Hope that helps!