@APinto the 3 y.o baby have minimum 15y just for the age to be able to sell the position, a long period where the best assett class are the stocks, if you educate him he will hold the position for other 5-10 year minimum, the same for the other kid, this Kids have a loooot of year in front of them.
Anyway, ok the diversification but 10-15 ETF? 1. World ETF 2. Bond inflation linked 3. Short term bond 4. Gold 5. Emerging market etf 6. A difensive ETF? Like utilities
What else? For a good diversification you need Just 4-5-6 ETF, not 10-15.