Welcome! And stop feeling guilty over a 2-wk notice: that's standard protocol. As to your question, a 0.6% ER isn't much for half your portfolio. Assuming your Vanguard ERs are around 0.1%, your weighted average is 0.35%...that's not bad. So, I wouldn't call it foolish.
But I gotta say, since you're already planning to re-balance 50% of your portfolio, it wouldn't take any more 'brain-power' to do it all ... and save several thousand dollars a year.
The Big Lebowski: Are you employed, sir?
The Dude: Employed?