I am a certified somm that worked at TW for two years after leaving the restaurant industry, led the wine program at my store, and taught classes.
Total Wine does get a higher rate on SD and WD products. This is largely because they control the distribution of those products, as opposed to third party distributors that take a slice of the profit. The owners/founders are also from PA, not MD. They absolutely train their associates to push those products, sometimes through questionable claims. I found quite a few of their WD wines were very good. Typically they were European families producing at a mid scale. TW would demand exclusive distribution of their wines in the US in return for wide scale distribution. The WD program also includes First Growth Bordeaux's and other seriously quality bottles.
SD products were more disappointing. Tons of bourbons that source from MGP. Labels that intentionally mimic major brands like Tower Texas Vodka (Tito's) and Lonehand Whiskey (Jack). The classes will only feature SD or WD products, and they offer free tastings of almost all Direct products. They train their staff pretty much exclusively on WD/SD products and offer bulk discounts only on those beverages. The stores keep metrics for % of sales that are WD/SD, and they reward the best performers in each region. I've had much better results with their WD wines than their SD spirits, but just ask for a taste before you buy, as some of them are quite good.