With DS2 I decided that naps that occurred when DS1 was napping would occur in the cot, bedtime would be a good set routine & all other naps would fit around the family routine... so if it was (as it was at times) catnap, catnap, good nap, cat nap, cat nap, bedtime, so be it... that middle of the day nap would outlast all the others so it was the most important, the others were in the car/stroller/sling/arms, what ever worked for the family.
I also tried to nap when both boys were napping so that I was less tired with the night wakings & I was then (hopefully) less stressed & more able to cope when the inevitable happened & there were times when he wouldn't sleep.