The GFI device they are all fed from may determine how many you can have on each circuit. Most devices are 6. CB different story.
7 and 8 is a bit too high. If this kitchen is big, with lots of counter space for appliances, use the "Thanksgiving method" for load calculation. (Or TLA, Turkey Load Amperage, it best to size the service for X-mas load amperage.) How much stuff can you have going on Thanksgiving? Micro, toaster oven, mixer, blender, electric knife, slow cooker, wok, turkey deep fryer? If you can fit all kinds of stuff up there, do your own per-counter-top-foot calculation, like 700w per foot.
With 17 outlets on 2 20A circuits, you could have a max of 68' of countertop, @ 70+watts fer foot. One could put a lot of appliances on 68'!
"Well - I oughta....." -Jackie Gleason