Not As Easy As It Looks
I often see newer players looking to pick two casters and building a pair of lists they can play and take to tournaments. Sometimes they are net lists taken from tournament winners, sometimes they are built to their own theory, and sometimes it's just dependent on what they've got. I wanted to go over some of the general list building theory and start a discussion on how best to make a two list pair for Steamroller and Masters tournaments.
Net List Best List?
The easiest way to build a two list pair is to simply steal it. You can find a lot of lists online that have done well at tournaments for any faction. Setting aside issues of uniqueness and dark horse power, these are lists that typically have been honed, practiced, and targeted for the player to win, and are backed up with some measure of success.
However, Warmachine is not a game where you can just pick up a list and expect to do well. I remember playing against someone who took the pVyros, double Hyperion, Imperatus list that was popular last year to a tournament. I played Garryth, a practically unknown and unloved caster, and ended up stomping him. It isn't that my list was better, or even a counter to his. But I knew how my list worked. I knew what it could do, how to do it, and what to avoid. He didn't have the same familiarity with his list. What mattered in that game wasn't our lists, but our expertise with the lists.
Still, net lists can be very valuable if you spend the time with them to understand them thoroughly and learn to use them. This is doubly important in ADR, where you make game deciding choices before anything has been put on the table.
Building a Pair Starts with One
Whether you go with net lists or build your own, it is important to start with one caster and one list. Focus on that list. Play it into everything. Play nothing but that list for a month or more into everyone. If a local tournament allows it, play only that list for the entire tournament. What's important here isn't learning when to drop which list, but to familiarize yourself so fully with one list that you can play it competently, win, and recognize its bad matchups and why they're bad.
Besides, you might be surprised. I thought my Issyria jack heavy list with a Hyperion and Discordia would be awful into Cryx originally, but it ended up being much better than I expected. With a few ADR changes, it turns out that I think it's even better than my previous Cryx list.
Expand into the Second List
Once you become confident in your first list, set it aside and start playing your second. You don't have to completely master the first one, just get comfortable enough with it that you can recognize its strengths and weaknesses and play it well. Then you do the same for the second list.
If you're building your second list, build it around what your first list can't handle. The goal is to have two lists that together give you the best chance of winning. If your first list is a ranged heavy army that can't see stealth, build something that can deal with Lylyth2. If Cryx Bane spam bogs up your first list, get a lot of infantry clear in your second list. The idea is to use everything you've learned about your first list to guide what your second becomes, then practice it into everything so you can become just as familiar with the second one.
Build, Play, Revise, Repeat
After you're comfortable in your two lists, play them both into appropriate matchups. Travel when possible and get broader exposure into playstyles and builds. It will take months to get there, but you'll start seeing results and improved success from your practice. Then start revising. You'll discover that you don't need that second arc node, or that rough terrain is an issue. Lists aren't stagnant, and new releases often have a huge impact on them. What used to be a good Circle answer suddenly stopped working when Bradigus came out.
Your lists should be constantly evolving into what you need them to do. While it is possible to achieve an enlightened, zen-like state of perfection with a list or even a pair, you'll likely eventually get bored of it if you don't expand and try out new things. Even if you don't get bored, becoming predictable is a weakness, too. Try swapping out one of your casters for another, or play two entirely new ones to see if one of them would work better with your first list. Avoid stagnation.
This is doubly important when working with a net list. Whoever made that list made it for them, not for you. If you think you need to change it up a bit, do it!
That's how I work on building my lists. It's a really fun process that I find satisfying and engaging. I learn a lot about the game by trying out extremes and things that should be bad and trying to make them work. My current Issyria list never would have existed if I hadn't gone to the extreme end of 45 points of jacks and support in a list, and my Rahn list wouldn't have existed if I hadn't tried to make Stormfall Archers shine outside of Ravyn. But trying out new things and seeing how I can make them work is what helped me build my favorite lists.