I got a new lawn in my backyard last year. Part of it sank over the winter (about 10ft by 10ft area). I put top soil over the sunk part yesterday. When seeding this new part, do I have to use the exact same mix as the landscaper used for the rest of the lawn? If I use a similar mix but not exactly the same, will it look bad? For example, if the landscaper used a mix with 20% Goldrush Kentucky Bluegrass, what if I use a mix with a different variety of Kentucky Bluegrass? Will it make a difference in the way it looks?