Sure, if it works for you, it works for you. Just wanted to point out that the method is quite a bit more expensive, so people can make informed decisions.
On topic: Now that I have Magna, I was wondering whether leveling rush and active would be a good investment. I kept blue Magna at 1, but I also use her on defense and want the AI to rush/active as little as possible. Red Magna seems good for attacking, so it might make sense here to max them.