Blue Origin is proof that just throwing money at a problem does not achieve results, and saying the Musk's only contribution to SpaceX to was "using his money to buy success" is a fallacy.
I don't how much you can look into his "engineering" prowess.. but clearly it was more than zero.
Bezos' thought that if he was a benevolent benefactor and a good money source, if he gave Blue Origin a blank check and let them loose to "do rocketry", he would get good results.
But his laissez-faire approach didn't make him a good boss, it made him a bad one. Blue Origin runs along like a headless chicken. He wouldn't have tolerated this shit in Amazon, why does he tolerate this in Blue Origin?
But Musk proves that you need to get into the weeds, you need to manage it yourself, and ask the weird questions no one else dares ask.
It's one thing to look at an invoice for a "rocket radio" for $25k or whatever and go, "I guess that's what it costs, here is the money, go buy two and a coffee for yourself".
It's another thing to go "hang on a second! why exactly does it cost that much, why can't we use a $600 one that's commercially available?"
Musk gets a lot of flak for not "listening to the experts" but him ignoring them and asking "but why?" like a toddler is what allowed SpaceX to massively cut not only cost but also time, a far valuable thing.
This meant he did a lot of stupid things... but it also allowed him to discover a lot of pitfalls where a commercially available part was just as useful for the task as something "rocket grade".
There are two anecdotes that prove this. (giving the cliff notes version, you can read his biographies to learn more about these)
In one test, he tried to fix something by cutting away the broken part and taking the fuel penalty caused by the part being shorter (but still under the fuel budget margin).
Naturally people said you shouldn't try such hacks and should just replace the part... but he tried and it worked and even NASA was impressed by it. He ended up discovering his margins and saved time, allowing them to proceed through the rest of the testing process.
In another test, he tried to fix something by trying to glue something that should have been replaced. It ended up failing, and rightly people would say he was stupid to not listen to the experts... but here is what I took from it.
For one, Bezos wouldn't be caught dead trying to glue things himself, he would never get his hands dirty like that...But then he wouldn't even what part was broken to attempt a hack anyways. He doesn't have the lay of the land like Musk does.
But secondly, it shows how two billionaires with open chequebooks approach things differently. One would just cut a cheque to replace it, but learn nothing new... another would say, sure I will cut the cheque afterwards, but while we are here, why not try something risky?
If it works, we learnt something new, if not, I had the cheque book handy anyways.
I feel this approach is why SpaceX works. YMMV
