Would Valois Poland be better, hard to say, considering he never actually reigned in Poland for long. Granted, Henry III remaining in Poland does mean he doesn't get killed in 1589, but at the same time, for that to work, it would require Charles IX to live longer (no Saint Bartholomew's Day Massacre and no tuberculosis) or alternatively, for Francis II (really hard to borderline unlikely) or Louis of Valois (if king, styled Louis XIII) to survive...