If you can take two clones and have a 95% chance one of them will survive, you don't need a mother plant.
When I first started, I would take a clone around 4 weeks into veg and plant it, Then I would take 2 more clones right before flower. Depending on whether the flower room was getting full or not, I would keep either the first clone or one of the second set of clones. If both tries fail, one still has a chance to take 2 more sets of clones in flower. That is a whole bunch of chances to get a good clone.
Genetically, a clone is as good as a mother plant. It's small enough to hold in one's hand. It doesn't need any nutes and is less likely to harbor mites and harmful insects. A 3 month old clone is more likely to produce clones than a 3 year old mother plant.
As I said before, the major advantage of a mother plant is to be able to take 10-20 clones at a time.
Adding a mother takes a plant out of the stream of plants headed towards flower, so you need to grow one more plant.
You can try both techniques on the same plant. With a plant in flower, and both clone and mother in veg, when a free flower spot opens up you can choose to flower the mother (big yield) or flower the clone (smaller yield if it is small.) The choice you make on run #3 might be different than the decision you make on run #5.
Saving a plant as a mother is a way of putting your harvest of that strain on hold while you try another strain.
So is taking a clone of a clone in veg and pulling the mother plant instead of putting the plant into flower.
It will all work out - part of finding your own style and pace of growing