Do universities favor experimentalists over theoreticians?
Potential for grants is surely something that universities consider, but I think your analysis is too simplistic to lead to the conclusion "universities prefer experimentalists".
For one thing, a department typically needs to offer a range of courses involving both theory and experiment, so they need faculty who are qualified to teach them. The decision to hire in a particular field is more likely to be driven by academic needs, and so the question of whether to hire a theoretician or an experimentalist probably doesn't often arise as such.
Another point is one you raised yourself: Experimentalists need more money than theoreticians. This cuts both ways.
Suppose they hire an experimentalist. First of all, she is going to need a big start-up package from the university in order to get her research to the point where she can get grants. There's a risk that she won't ever get to that point, in which case the university's investment doesn't pay off. And maybe she does bring in some big grant money for a while, but years down the road, maybe her funding dries up. Maybe her research area just isn't as hot anymore, or funding agencies are preferring to go in a different direction. Without major funding, she can't do her research at all, and now the university is stuck with an unproductive faculty member. So hiring an experimentalist may be high reward, but also high risk.
By contrast, a theoretician doesn't need a large short-term injection of funds, and they know that she will be able to be productive regardless of what happens to her funding.
Sorry, but the question seems to imply some misconceptions about the nature of (most) universities. The use of the word income, rather than revenue suggests that you think of them as businesses generating profits and that overhead represents profit. This is mistaken. Overhead is charged to cover costs, not to provide "profit". Universities have no owners or shareholders. Every bit of revenue generated by university activities gos back into current and future university activities, though there is some redistribution of funds between those activities.
There is no financial reason to prefer one activity over another. Universities like grants so that the kinds of things they want to actually do can be adequately funded. You can't run a cyclotron on no funds and those funds need to come from somewhere. If you can't find the funds, you can't do the research in those fields. And that cyclotron has to be in a building that has to be heated and maintained and it sits on valuable real estate. That is what "overhead" is about: covering costs, not generating profit. If that didn't happen, and grants had to cover all their costs, they would need to be hugely larger. Ok, you have three million Euro for your new chem lab. Now, where do you want to put it?
A university is a public service organization, not a business. It exists to provide an educated populace and to do research that, hopefully, will benefit society as we move toward the future.
For a (slightly) more direct answer to your question, note that theory drives experimentation, just as experimentation drives theory. Balance is needed, and, I think, recognized.