It should be fine. Think of the government bonds like a hedge.
The most important decision is how much stock to have vs. how much bonds. Beyond that, the difference it will make to your long term return with exactly how much short, medium, long, government vs. corporate, TIPS, GNMA, etc. (as long as you're not super-heavily weighting the riskier ones) isn't going to make a huge difference. I wouldn't sweat it. It's just like picking an S&P 500 index versus a total market index for stock; there is a difference over the long term, but it's not like you'll end up poor because you chose wrong.