Even plants that don't need a lot of water and can take full sun when they are established need a good, deep, thorough drink and shade when first transplanted. Also it is unrealistic to expect plants to visibly grow when first transplanted. I suggest you give them a very good watering and keep them out of direct sun for a week or two. And in the longer term the pot is not going to be large enough for those three. It would suit the rosemary by itself.

I don't know about your layer of leaves--they do need their soil to drain well, and you don't want to lock too much moisture in. I used to try some gravel in the tops of my pots, but gave up since it was too hard on the arid herbs and didn't do much for the fungus gnats anyway.

Question--did you give them a chance to acclimate to the full sun exposure? They may be a little sun shocked if they're used to not so intense sun with partial shade. In my experience, droopy rosemary is usually thirsty--it's how I know to water my indoor pots, when the new growth tips droop slightly. It could be that the root system is just not used to having to pull from the larger pot--did you do any root trimming when repotting? Root rotting rosemary will show by having the leaves brown from the tips in, and dried out rosemary usually just gets crispy, the most common problems which it doesn't sound like you have. Probably just needs some time to get used to new pot. Sounds like you're being careful with the watering, etc.

I have never kept my Rosemary cuttings on the dry side. But I usually take quite a few cutting from the parent plant and just let them go on their own. As for oregano and Thyme I go to any big box store for starter plants and have never had a problem. My Greek oregano went from a 3X3 inch pot to 4 by 4 foot plot in less than 2 years.Now Sage I have always started from seeds but they sometimes just up and die, but then the cuttings I saved took care of this problem so far. But so far my Chives and Thyme only last a couple years before they leave me. The joy of gardening always has it ups and downs but I keep trying to learn.

You do need more time before seeing a growth difference, especially in the rosemary, which I believe is the slowest-growing of the three.

And although the plants had been outdoors for a month in morning sun, full-on afternoon sun is still a different story (not to mention that about 1 month ago, the temperatures, even in full sun, were probably quite different).

You combined a transplant and move to full sun at the same time, so some problems are to be expected.

Since people are finding this old post, I had better update it! On the advice of some people here at Garden Web, I let the rosemary have this big pot all to itself, and moved the thyme and oregano back to the east-facing porch, each in their own containers. I also have another rosemary planted in the ground by the east porch.

All the plants are doing quite nicely now. The rosemary is three times the size it was in this photo. I don't know how fast oregano is supposed to grow, but it's healthy and about three times the size in this photo, too. The thyme stayed the same size for a long time, and now it's suddenly growing a lot.