The only way that you will get them in focus/sharpe/etc is to try the following
position yourself in a level plane with the subjects ....... i.e. flat onto them .......... that's probably the most important. ........ because that close even at small fvalues to DOF is very shallow.......... before you tell me so, I know it's difficult
use the smallist f value that you can manage, i.e. f16 minimum
use a reasonably fast shutter speed
use a small tripod as a "prop" ... with a "loose" head .........if you know what I mean
200mm is fine, (what you have used) .......... I tend to use 300mm sometimes with a 1,4 TC - i.e. 420mm ........... I have never had particularly good results with a dedicated macro/micro, say 105mm lens
don't worry about high ISO's to start with .. concentrate on getting a sharpe and in-focus image
look at your results, in particular the DOF, figure out what's wrong ........ and don't alway think that you have to focus on the head
experiment using a flash ..... either the one on your camera or a separate flash