1M and 1W very seldom occur on the same day as 1M is either 30 days (Time) or the number of days in the month (Time - Key Date).
So you would probably need to create a strategy-based maintenance plan using 1W, 4W, 12W, etc packages.
In the strategy (IP11) the 4W package would have a higher hierarchy than the 1W package.
PeteA