Royal Chantenay produces a short but fat root as much as 2-2.5 inches across. For the carrots to develop well and gain proper size, thin to 3" apart. If you want to harvest before they reach full size and development, you can allow them to be just a bit more densely planted.

@gardengal48 (PNW Z8/9)

what’s a more traditional looking carrot that has a good production rate?

Chantenay type are good quality, easy carrots, good for new gardens. Scarlet Nantes are not as thick of a carrot, are also good quality carrots you can easily grow. If you want good looking, good sized carrots you give them a little space. If you are not that particular, you can crowd them. Good sized, uniform carrots are easier to clean, and look good.

You can space them 1" to 2" and pull every other one when they are smaller, then let the ones left get big. Easier said than reality, but I try that in theory. I'm never ruthless enough at thinning them, and I always wish I had thinned better. Quantity versus quality.