PATTERN files

Does anyone know if there's an easy way to specify use of one pattern file and/or to update all hatch patterns in a drawing to come from one or the other (similar to the line files .lin) - either acad.pat or acadiso.pat. Starting a new drawing works fine, the hatch is basically the scale of whatever drawing you are doing, but cutting and pasting from other files, the same hatch shows form both acad.pat and acadiso.pat., so for example the hatch DOTS could appear to be the same in 2 drawings, but have different scales of 1.00 and 25.4. We do a lot of metric drawing sets and imperial drawing sets and it gets sloppy when people try to matchprop hatch not knowing it may be from the other pattern file. Any help would be great.