I would highly recommend avoiding alt-coins. And it would not spread the risk to buy multiple alts since they are all based on the same technology. Want to diversify? Buy some bitcoin, gold, real estate, stocks, etc.
Interesting opinion. Perhaps your examples are really the safest scheme where the risk is minimized. After all, diversification can bring clear advantages to the participant and increase the stability of income, but requires a detailed assessment of domestic resources, environmental factors and deep knowledge of market trends.