Under what circumstances should I buy a new dog in Dog Sled Saga? I'm currently on my 107th day in League 2 with the same 3 dogs I started out with. I could pop up to League 3, but I'm not sure I want to pay the higher dues yet.
My current team's training seems to be going well, as I've got Natural dogs for 2 of the positions and an Able dog for one of them. Their happiness is on average Good to Great, their Rapport is at level 2 with each other, Fatigue Capacity is level 2-3 across the team, and their skills are at level 2.
If I buy a new dog now, they're going to be starting from the beginning of leveling up and will be a bit behind my other dogs' skill levels, even though I'm doing harder races now. I see you can breed dogs, but you need at least 5 dogs total to do that and I don't have the finances to pay for the League fees or buy the kennel room yet.
At what point in my progression is it a good idea to start expanding my team? Are there other factors I'm overlooking here?