Just an observation:
You can macro /recast on your strategems to see how much time is left before you get another charge. I have a macro to just /recast Penury and then /recast Parsimony so I get the time whichever art I have active. Here is the thing: Whent I recast and have -1 or -2 charges it only hsows the timer until the next charge. When you /recast and have 0 or 1 it will actually show the number of charges you have.
[Penury] 2:34 (0)
Assuming you are not in negative numbers, you can use recast to find out how many charges you have available at any given time...