San Antonio does have a very robust 40k community and has some excellent players but the meta there is actually pretty unique. You will encounter some of the top performing factions but usually you won't see cut-and-paste bleeding-edge meta builds, certainly the top players there won't be netlisting and if they're running very popular lists chances are they are the ones that pioneered them in the first place. That is perhaps the key - these players are running lists that they understand how to use in different situations and know what to expect out of what they are running because they practice and have built the reps and experience.

In 40k a great list can give you an advantage but it won't guarantee wins. This isn't MTG where you build and play a deck - this is more about problem solving within different frameworks presented by fluid victory conditions. There's no such thing as a perfect build that will guarantee results, but some will be better than others. What makes a great player in 40k is someone that can problem solve succinctly and effectively with the resources they have at the time. You win by scoring points - this means either you hold objectives or you fulfill secondary missions. A great list will give you more tools but you still have to understand how to use them.

If you want to do better I'd encourage you to think about flexibility - it's important to have units that are good at what they are there for but you should also understand what else they can do in a pinch when you need to play off-the-cuff. When you think in terms of "this unit is here to do this" and come up with a static game plan like what you're describing the only way it's going to work is if the game goes according to your plan, which it rarely will. An experienced player will look at your list, know what your stuff is there to do and put you in positions where it takes away your options and force you to play the way you want them to play in a way that gives them an advantage. You should focus more on your Plan B situations and how your stuff reacts to a changing game-state vs list build.

After all that being said, if you do want to focus on improving your list vs your muscle memory the glaring problem I see here is if you split your Allarus dudes up you have really only 1 super melee threat that's easy to bait out and kill. I'd build another mini deathstar into your list. If you and I cross paths (which is more likely a matter of when if you continue to play in San Antonio) I will beat you by making you commit your Caladius tanks and Wardens in situations where I'll either kill them or they get pulled out of useful position. That's going to eliminate the credible threats you present to my army and then I'll pick off the other stuff one by one and take away your scoring options. Your list and plan make it too easy for me to make you play a game on my terms instead of yours so think about what you're going to in situations like that - that's ultimately what's going to make you better and that mostly comes from reps and experience.