Except a shield is merely a piece of armor, while a banner is meant as an actual representation for their group and is far more up-to-date. You’re the only one claiming that Blue and silver is somehow an exclusive theme for High elves when we have literal evidence that it’s not. Even the Silver Covenant themselves are seen wearing blue and gold.
Why do you keep saying this? Who is saying we shouldn’t get these things? I’m pointing out that people are intentionally excluding other themes people want because it suits their agenda, that’s all.
At this point none of the themes have been added, so if your genuinely interested in showing good will towards the players by making a list, include them all and not just the ones you personally want most.