In my opinion, investing money that isn't mine into something too speculative is a huge no-no. Why not just use your own money instead? That way, you don't receive any crap if ever the investment goes bad. They already aren't convinced in the first place, so why force them?
This would be the key point I think.
Putting it aside, I don't know why the OP brings land into the equation, unless it is so cheap that you can buy chunks of land for $50. The normal is that you will have to save several months at least until you can buy something, whereas gold and bitcoin you can buy small amounts. The downside of gold is the premium he will pay both buying and selling and if he does DCA bitcoin he should think about buying a HW.
The rich men are actually buying lands particularly the country side properties since its the last that will be affected when there is uncertainty like ww3. Some of them are buying lands or islands in Hawaii or so.
Sometimes the rich men are even buying yatch although we know this is going to be a liability in the long run but it make sense during war for they could just travel on their own with it to safety with their family.