You seem to be thinking along the lines of beer making Frank.
If you mix up the batch to allow for 3lb "in the gallon", that's a good starting point.
If you took a yeast that will do 14%, presuming that you like a medium level sweet mead, you'd want to have a final gravity of say about 1.010 which would mean that you'd need a starting gravity of 1.114, because a drop of 104 points equates directly to 14.1% ABV - now that is doable, as a start at that level is reasonably easily manageable, but if you chose a yeast that will do 16% or 18% you start to look toward fermentation issues straight away.
Now it's usually easier to start lower if possible, so a correctly managed must for 14% could easily start at 1.094 with a final at 0.990, which still gives a 104 drop so the 14.1% mentioned above - it makes for a relatively straight forward ferment
So you'd work on that basis to calculate the nutrient levels for that (read the
NewBee guide if you haven't already as there's lots of tips for easy fermentation management there as well as doing forum searches).
Hence you can make any yeast, make a batch which is as sweet or dry as you want, but the more sugars at the start, the harder the yeast has to work. Which is why it's often recommended to start a bit lower.
Even for a yeast that will go to 18%, you can still start lower and either work out the total honey requirement with the mead calculator, so that you know (roughly) how much honey you'll need to get a batch of a certain size up to the level you want, or you can just start at a sensible level and then add honey in increments later on. As long as the yeast have enough nutrition via energiser and nutrient (or if using only one type, then the one commonly called energiser, which is a tan/beige coloured powder usually is the one to go for). Adding more honey later on while the ferment is going, is known as "step feeding".
You can even just start lower, then keep step feeding until the yeast dies. Don't forget, the published tolerance numbers for a yeast are only a guide with meads, the data is derived from grape musts as far as I'm aware. Yeast is a living organism, so you can't just tell it where you want it too stop - many people have produced batches that appear to have exceeded the published numbers by 1% or so
The technique I generally use is to make a batch to between the 12 and 14% mark, ferment it dry, then rack it off the lees to secondary, hit it with stabilising chems (sulphite followed by sorbate), then back sweeten it to about the 1.010 mark (which is where I like my meads i.e. that's sweet enough for me). You may also read about the possible problem where sweetening a batch with honey, can cause a haze in a cleared batch. That is a protein haze AFAIK, and because it can be a pain to have to clear a batch twice, well that's why I sweeten at that stage, so I only have to clear a batch once - which also helps to reduce production loses.
Before I forget, also either get some pH test strips for the 2.8 to 4.4 range or a cheap pH test meter (a pocket one is usually cheap enough) and some potassium carbonate. If you mixed honey and water to about the 3lb in the gallon level, you will find that it will often give you a pH reading in the mid 3's, which is the ideal level for wine yeasts. Meads are funny beasts, especially traditionals. The pH can swing quite a bit and if it dropped below about 3.0 it can cause a stuck ferment - which is where the potassium carbonate comes in, as it will raise the pH. Also, if you read up about early stage aeration i.e. stirring or blitzing the must with a spoon or even a stick blender, once or twice a day generally (if you did a search you can even read about people bubbling pure oxygen through a must, using a stainless steel airstone - which is a bit over the top for my liking). This is for yeast development, but it also has a beneficial side effect whereby it disturbs the ferment so that CO2 bubbles come out of solution. The dissolved CO2 is also known as "carbonic acid", the disturbing of that helps toward preventing the pH dropping too low as well. It's wise to know that, because if you followed a staggered nutrient regime, where you'd load most of that into the must after the lag phase, when it comes to adding the last of the nutrients etc, by just putting the powder straight in can cause a mead fountain - which is part of what I was driving at with that fermenter. A 5 gallon/19 litre batch doesn't leave much head room for foam - glass fermenters are even worse as the shape of them creates a jet and you can often read of quite spectacular mead eruptions/fountains.
Right, it's getting late and I can't think of anything further for the moment.