A few thoughts about goat development, milk test, and buck management.
Milk Test Results
Single kids are a huge bummer. They affect production, if they are on the doe they make the udder lopsided, and they are a bear to deliver due to being oversized. However, I was surprised to have singles from Sunny and Leia. Both had multiples last year as yearling first fresheners. I suspect a factor contributing to the singles was buck age.
Gunner was used heavily last year AND he's an aged buck (6+ years). Buck lifespans are approximately 8-12 years, compared to does who can live 15-20 years. One way that Gunner showed his age last year was by coming into rut later than the younger bucks, who display rutting behaviors in July. He didn't settle does until late-September. A younger buck settled one of my aged does by early August. I suspect that a second way that he showed his age was by a drop in sperm count when presented with nine does. I've retained a lot of Gunner doelings and an outstanding buck prospect, so Gunner's going to be used sparingly and strategically next year. The 2020 kidding season is going to be Panache's year, with a few does thrown Moonstruck and Jax's way.
Doe Development (cut them some slack)
I remember talking to veteran Nubian breeders back when I started in goats. They observed that goats who start out fast and strong sometimes don't hold up over time. It's also good to know your lines. The Manuka Honey line is slow to develop. I had one daughter who was less developed than my other does in the same age range when she was appraised as a 3 year old, then as a 4 year old she LA'd Excellent overall, excellent udder.
Take the Long View
It's hard to be patient, but it's so, so important. I KNOW that these does will finish with their milk stars and Excellent Linear Appraisal scores. They're that good genetically, and based on their linear appraisal scores. Now it's just a matter of being patient and doing the work to develop their potential.
Real Life (cut yourself some slack)
In my case being patient is particularly important because I work a very demanding job IRL (in real life). If I try to do it all in one year with my goats, I'm going to burn out. I have to pick my battles. Some farms can do a full 305 milk test (I do a mini-version), it's not going to be feasible for me until I retire, which won't be happening for a while. So, yeah. I need to remember to cut myself some slack.
So, if you're like me and have a lot going on in addition to goats, cut yourself and your goats some slack. Take the long view. Do what you can, and work on racking up small successive victories.