I'm sorry, you have to use the right tools for the job. In my opinion, skimping on overhead mics is a cop-out.
What if one or two cymbals are much louder than the others? Which way would you point that mono mic? You can't ask the drummer to move his/her cymbals closer to accommodate a single mic. The whole point of using two or more overheads is not just to create stereo imaging but also to capture all of the cymbal activity at usable levels. All cymbals play at different volumes. How will that little splash cymbal ever be heard over the ringing of an 18" crash? What if that ride doesn’t have much "ping" to it? Can you bring it out without making the other crashes sound harsher?
Sometimes, it seems like not enough attention is being paid to finding the "sweet spot" of cymbals. If you really took the time to sit and analyze the sound of the cymbals you've recorded, would you be completely satisfied? Ask that drummer if they are happy with the cymbals you've recorded. Do they sound the way they expected them to sound?
Yes, you've made it easier on yourself but, have you made it better for your client? Where is the quality in your workmanship?
Do what's right,
RawDepth