I would request near lobby or ready at checkin, whichever is more important to you. If you don't like the room assigned, you can always go to the front desk and try to get it changed at checkin.
If you request 'ready at checkin" or "early checkin" as a priority, it is my understanding that room assigners generally assume that this request is a priority over any other requests. Hence getting other requests becomes more unlikely.
Room assigners have to interpret what is most important if you give multiple requests. Some say to put your most important request first and limit your requests to 2-3 at most. Also, people say to try to be careful not to request something that doesn't exist. I didn't know that there were partial savanna view rooms for the deluxe studio room category, so I have no idea where they are located. Are any near the lobby?
My personal experience:
I have been lucky and gotten exactly what I requested once out of at least seven trips staying at the AKL. A few other times, I received a room that was almost what I wanted, but not ideal. Multiple times I have been assigned less than desirable rooms (from my perspective) and lived with it.
My philosophy:
Choose a room category where the worst room possible is at least acceptable to me. If I can accept staying in the worst room, then that is the category that I book. I love savanna view rooms, but they can be very far from the lobby. Due to mobility issues, being near the lobby is very important to me. So many rooms in this category are unacceptable to me. All pool view rooms are within an acceptable distance from the lobby, so I book pool view and request third floor, as close as possible to the lobby. (this is the request that I have only had once, but it was wonderful!)
Good luck! Wherever your room is, the AKL is still a wonderful resort!