I also feel that it's better to keep investing in ethereum than to withdraw 50% and invest it in other coins, because in my opinion also that ethereum is better and has a greater chance than other coins. But, I think everyone has their respective strategies in investing, maybe according to him investing 50% of ethereum into other coins is an opportunity to be able to generate greater profits later.
You can only say that because we're not familiar with Titan coin. As OP said, he made his research on this coin and that results him to trust and have his hopes on by investing on this coin. Ethereum is indeed a great coin, but there are also some altcoins in the market that has a potential, for me, OP can go with this investment, since it is better to put his investment into different altcoins to have more opportunities of making a profit.