I can see that this level is going to be unstable at best - too bad. BTW, I wasn't able to even get R across let alone Z with B alive.
Getting Z across the ditch is a matter of patience. Getting R across is more problematic. If the crossing is successful, R seems to be drunk and misses the stairs.
Got it! R does not cross the ditch at the same spot as Z and needs a little encouragement to take the crucial step. B must then be quick.
