There are many other factors just as important as cloud base if not more so.
Firstly how skilled and experienced are the crew? The secret of a good landing is a well flown approach.
It's no good popping out through the cloud unless the runway is where you expect it to be, or unless you stand a good chance of getting it back in the slot.
If the A/c has an autopilot approved for non-precision approaches and good secondary information such as drift information, gps for distance guidance, etc. then you are going to stand a much better chance than if it is being hand flown using just a wobbly NDB needle and a stopwatch.
What are the runway markings and lighting like? You are much more likely to see a well light runway with clear markings rather than some obscure bit of concrete.
Are the pilots familiar with the field, i.e. is it their home base and they are going to get used to the local landmarks? For example on runway 06 at Inverness which had an NDB approach there was a very distinctive chimney which helped orientate ones-self in poor visibility.
In short I suspect that the cloudbase oktas has a relatively small input into the success of the operation.