In my opinion it sounds as if you are trying to do too many things, too soon, with your small band of Dwarves. I start with a totally unskilled seven. They own seven picks and two axes, a rope and an anvil. I set them, using Dwarf Therapist as you do, to mining, carpentry, masonary, architecture, mechanics, butchery, tanning, and farming.
The only carpentry I do for the first half year is to make a bucket and to take apart the wagon. The masonary consists of making one block, between one and three floodgates, and perhaps a door or two. The mechanics consists of making between four and eight mechanisms, building a lever, and attaching it to between one and three floodgates. There is also the well to be built, and the farming plots to be laid out. Plump helmets get planted in a 5x5 plot. If the pasture is dangerous, then the two draft animals must be butchered and their skins tanned, before they either starve or are killed by ... whatever. The axes are only used to clear trees that are in the way of something else that needs doing, such as digging a channel to let water into my reservoir or walling off a stairway from a cavern.
All the while these various cross-crafting skills are being practiced, huge amounts of mining gets done. Because all seven can do any of the other tasks, the only thing they get good at is mining. Then, as migrants arrive, the other professions are offloaded onto the newly arrives Dwarves. There is no feeling of loss because there was no real skill acquired in anything but the mining for the first seven. They may all get a tiny dot in planting, but it will be nothing compared to the large square in mining. They may also briefly be used for emergency professions, such as gem-cutting if there is no jeweler and someone's mood needs a cut gem. They are jack-of-all-trades and master of one, at least until a specialist arrives.