Craig, trust the Maverick. I have three therms going right now in my 22.5" WSM, the lid therm, my Maverick, and the BBQ Guru DigiQ DX2 air pump. The Guru is set at 235 and that's what it reads. The Maverick is reading 239. The lid therm is reading 225F. I choose to follow what the Maverick is telling me and just make a mental note of the lid therm. The Guru is there just to maintain temperature.
I don't use the Minion method but many do. I'll only give something a chance once or twice, and if I can't make it work like described, I go to what I know. I dump a bed of cold charcoal with buried wood in my WSM, then dump 1/4 to 3/4 chimney of hot coals on top of that in the center of the cold charcoal, depending on the chamber temp I want (1/4 for 225, 3/4 for 300+). I really don't spread it out much, just making sure it isn't high enough to touch the bottom of the water pan.
I like the dump method of loading because it provides more airflow and surface area that can burn in the charcoal. Densely packing charcoal is not conducive to a good, clean fire.
Placement of your Maverick probe can impact temps too. Close to the meat will read lower than a couple inches away. Placing it close to the edge will read higher than placing it in the center of the grate. Pick a spot and always put it there. I place mine about 3" from the edge.
At this point you want to raise your Maverick temp, what 25F? Open your lower vents fully to raise the temp 25F or so, opening the top vent to match. The temp may drop initially but should start to rise as the coals burn hotter. Then when you are within a few degrees of your target close down the bottom vents to 1/4 or so and then close the top vent to 1/2. Adjust the top vent as necessary to get it to stabilize.