pexinfo.com has a chart that shows what is compatible with what as far as fittings and tools.
Wirsbo is best hands down, but not available everywhere and it is expensive and not as compatible as other crimp style brands.
Using the proper fittings, tools and pipe for a new install is the best way to go, stick with one system. For repairs then check the pexinfo site.
You made a repair only so if it was necessary probably OK, I wouldn't use the compression style fittings, crimp or Wirsbo expansion style only on PEX. I would hate to have a leak above a water heater.