I think it's probably because Midoriya is a Japanese surname meaning "green valley". Both characters have green as a prominent color in their design. If you really wanted to read further into it, you could say that "valley" is appropriate for Izuku because it indicates depth, and his potential was far greater than what it appeared on the surface. Also, Midoriya is a fairly old surname in Japan, which makes it appropriate for Tatsuki, since his family runs a generational business. And now I feel like a weeb.