> For example, in 해 he the ㅎ andㅐ letters are both the same size. When you write 핸 hen, see how the h especially becomes smaller? In typewritten hangeul, that first consonant is always that small, so you can use only one size of initial h and so on.

I see the opposite. As those characters render in whatever font my browser picked, the ㅎ in 해 occupies much less vertical space than the ㅐ does.

In the 핸, it still occupies less vertical space, but the difference is smaller. It's about as tall as the left-hand bar of the ㅐ instead of being significantly less tall than that.