The comments in this thread got pretty wild. I'm a little scared to, but I'll weigh in a little bit as a professional computer architect and former (adjunct) professor of computer architecture. I'm going to assume that the original question is about CPU architecture, although the OP doesn't actually say that specifically. In general, I think /u/Veedrac got more right than /u/AttilaTheHug Sorry if that offends anyone.

If all you care about is clock speed (which is all the topic's original question asks about), then basically the sky is the limit and you can make any width of architect run at any frequency you want through egregious pipelining. If you actually care about overall performance, then ridiculous pipelining to boost frequency is going to hurt more than it helps. You need a more balanced approach. I think that's where the disconnect between our two most vocal responders lies.

Real CPU products are generally not created to hit arbitrarily high frequencies, and they actually have more sensible performance and power targets. Their architects and designers explore many complex design spaces to try to balance many competing priorities, and they generally succeed.

In support of what /u/Veedrac said, and to refute the premise of this topic, I would point you to every single big.LITTLE-style of architecture that I know of. Universally, the higher performance wide core is clocked higher than the narrower low performance core. This is true for ARM, Apple, and even Intel's Lakefield. AMD doesn't have a big.LITTLE-style SOC, but their wider cores like Zen and Bulldozer always clocked way higher than their Jaguar cores. The wider core always has a much higher clock frequency.

You might say that this is due to the differing design goals between big and little cores, and you're exactly right. Both the big and little cores have sensible performance and power targets that they were designed to. The architects decided that they wanted their high performance cores to get some of their high performance from high clock speed, so they did what it takes to design them for high clock speed. They decided some of the power savings of the low performance cores would come from running at a low frequency, so again, they designed to that point.

When you look at multiple cores designed by the same manufacturer, it doesn't support the premise of this topic, but if you look at high performance cores by different companies, then you can see a little bit of this in action. Apple is going for very wide and moderate clock speed, and AMD and Intel are going for moderate width and very high clock speed.

I think I'll end with this: Ultimately, the OP seems to be more of a theoretical question, so I think a more theoretical answer is appropriate. In theory, there is no relationship between width and clock speed, as long as you don't care about performance. If you do care about sensible design points, then the market is full of examples of moderately wide CPUs clocked extremely high, and narrow cores clocked very low.