So the big question is, what is best for this 401k?
No, the
big question is "what is best for my entire investment portfolio? What asset allocation to I want?" Then what to do with your 401(k) is a subset of that larger question, and depends on what you do with your other investment accounts.
It sounds like you probably don't have any other investment accounts yet (IRAs, taxable accounts), so the 401(k) is your only concern, but you should still think about it in that wider context to prepare for the future. Often, if your 401(k) only provides one fund that matches your desired asset allocation, then you would invest in that one option in your 401(k), and use other accounts where you have more choices (like an IRA) to fill out that desired allocation with other funds. In your case, if you really don't like your 401(k) choices besides the Vanguard fund (it would be good to see the expense ratios on all the funds), then you could potentially contribute there up to the employer match, and then fund an IRA to get you to your preferred balance with bonds and international stock.
But to my eye, I think you can get your desired allocation within your 401(k). PIMCO Total Return (which is a bond fund, if you didn't know), Vanguard S&P 500 Index Fund, and Dimensional International Value Fund would cover your desire for Bonds, US Stock, and International Stock, respectively.
Either that, or just pick one of the T. Rowe Price Retirement funds and put all your money in that.
It really makes no sense to be invested in a Target Retirement fund AND other funds. Target Retirement funds are intended to be single-fund solutions. If you instead want to be in control of your own asset allocation (which you seem to), then just do that rather than mixing the two strategies together.
I'm not a fan of T. Rowe Price's version of target retirement funds, since they invest in an giant number of sub-funds, many of which are managed and expensive, and contrary to the idea of the simplicity of an all-in-one fund in my mind. But if there is one that meets your desired allocation, and its expenses are better than your other choices, it's certainly worth considering.
