A expirenced horse with a educated rider can figure out there own strides. Although some horses, no matter how much they jump keep getting the strides wrong, but this can also involve a un balanced rider. If you can not get two jumps in a row, yes then a suggest a pole, where ever the next jump is. Do you know how to count your strides? Between jumps, do you know how to slow and fasten up?
A great Showjumper told me this " A Showjump course is just like a Dressage test, but with obsticles in the road" in other words you ride just as if you where riding a test.