It depends. My best managers have been engineers. You generally don't need a full time engineering manager for a small 4 person team. If you do, your org is probably dysfunctional.
I will say though, if you're going to do both, do a good job, meaning one you'd expect of your reports. Don't be a manager that hands off his half-working project "to take it over the line." Finish your work.
Right. The other comment said that people don't move into management because they are a great engineer. That doesn't mean managers haven't been engineers.
I'm happy to say that one of my managers was also the best engineer I've ever worked with. He told me he didn't really like managing but basically did it because he didn't felt like he had a choice.
I will say though, if you're going to do both, do a good job, meaning one you'd expect of your reports. Don't be a manager that hands off his half-working project "to take it over the line." Finish your work.