it's easier when you have someone present to make quick adjustments on the fly

Even in Apollo the humans were pretty far out of the loop. They had landing site selection and some variable thrust control. Their option was to trip an abort switch which would then automate the abort procedure.

The Russian probe that got pancaked last year might have been saved if someone had been on board to realize the automatic system was not functioning.

It might have not crashed into the moon. The ultimate result would have been the same. They wouldn't have had fuel for a second chance, the abort procedure prevents you from slamming into the moon, but it doesn't care about your ultimate orbit, so tons of station keeping would be required just to try a second time, and there's no recovery mission that's going to go get the thing.

It slammed into the moon because there was no point in adding an abort system and it was the most cost effective solution given the above.

That's why I said putting a craft on Mars is relatively easier. I was referring to a side by side comparison, not the trips required to get there.

To put something somewhere you have to get it there. You can ignore that as an engineering challenge if you like, but then your analysis will be wrong.