The problem is that Steam is only used for the initial install of Lotro, it doesn't handle, or even knows of subsequent updates. So the verification step will effectively downgrade your Lotro install to the originally installed version (which I think is U7), and when you then start the Lotro Launcher it will upgrade it again to the current state.
Would be nice if Lotro could be integrated properly into Steam, but I guess it's too much effort on Turbines part.
Used to play: 85 Champ / Captain / Runekeeper / Guardian, Guild Master of everything but cooking.
Playing now: Hellcat / King Tiger / GW Panther / IS / KV-5 / M4 Sherman and more