Sure you can. If you want to work them next to each other, it's not an issue.
If you're working them one on top of the other, then just increase or decrease, whichever will change the count the least, and then continue.
So let's say that the 8 + 5 takes, oh, 85 for 10 repeats.
ETA: If you're concerned about changing the count, then just add a couple of edge stitches in stockinette or garter to keep them even.
The 4 + 3 would work out to 20 repeats and give you 83 stitches, so you'd decrease by 2 and forge ahead.