I am interested in investing. Your explanation about the investment return is little unclear to me, especially part given below.
"... The original investor's 15 coins now make up 75% and the new investor's 5 coins make up 25% of the total bankroll. If now another 10 coins are lost by players, the first investor gets 7.5 coins and the second investor gets 22.5 coins, bringing their investments up to 22.5 and 7.7 coins respectively...."
In the above scenario given in your website, the second investor should earn 2.5 coins (not 22.5 coins, because 25% of 10 coins is 2.5 coins) and bring the investment of the second investor to 7.5 coins. Please let me know, if I misunderstand your description.
I believe the writer of that paragraph forgets about the 50% commission here, though he had that in mind when he was writing the earlier section and was talking about the situation with just one investor.
If some players have lost 10 bitcoin, the investors will only be able to share 50% of the profit, ie. 5 bitcoin only. The investor with 75% stake should get 3.75 btc while the second investor with 25% stake should get 1.25 btc.