These information layers should not be switched to data layers.
It's OK to switch these information layers to data layers.
If you are in doubt look at the expression(s) on the grid layer If it has a formula that uses a GIS function, the layer should not be a data layer. There is a list of GIS functions in the Argus ONE online help. Select "Function Reference" from the Help menu and then "GIS functions" to see it. CountObjectsInBlock is probably the most commonly used GIS function in the MODFLOW PIE. In addition, be cautious about changing layers to data layers if they use the "Exact Contour" or "Nearest Contour" methods. For example, Wetting Threshold Unit[i] relies on the Wetting Flag being -1, 0, or 1. If you switch Wetting Threshold Unit[i] to a data layer, the wetting flag won't be exactly those values because of interpolation.