I am looking to start putting some money into index funds via IBK. I'm looking for something stable and long-term. No day trading for me just yet.

The funds I am interested in are VTI, VOO, and VUG. Given their overlap, I am not sure how much it makes sense to diversify across them, but here is my current plan.
50% into VTI. Covers the whole market and its up and downs.
30% into VOO. Covers the top-performing companies, but a small spread.
20% into VUG. Covers high-growth companies, but more risk and smaller spread again.
Minor tweaking every few months based on recent behavior.
For reference, I am a US citizen, so trying to work best under those limitations. lol