I could easily be mis-remembering about the bacon grease. It's been forty years since I tried to make gumbo myself (which ended very painfully with a severe burn) and twenty years since I had my daddy's shrimp gumbo. I don't make it myself because my husband doesn't like shrimp.
My daddy made shrimp gumbo occasionally through the year, but it was our traditional Christmas Eve meal. I do know it had abundant shrimp (but no sausage or chicken), occasionally had crab meat, and definitely had okra, the "holy trinity," and a rich brown roux. I think he included some tomato, but I wouldn't swear that was true. It had a bit of a kick from the seasoning, but wouldn't scorch your tonsils going down.
I asked one of my Louisiana friends for her recipe yesterday and it had no okra or tomatoes. Personally, I consider the okra an essential ingredient, but I know some people don't care for okra. I looked up recipes on Southern Living this afternoon and found a recipe which sounded similar to what I remember my daddy making (which, Virginia, is similar to what you described in your post.)
All this discussion has me craving some good shrimp gumbo. It is not easily found here in north Georgia. We do have a "Cajun Depot" restaurant in town, but I've never tried their shrimp gumbo. (We don't go to that restaurant because of my picky-eater husband.) We also have a nice little seafood shop/restaurant but I don't know if they are open right now. It's very small and they may not be able to meet the Covid-19 guidelines. I've had their gumbo because we usually go there on my birthday but not this year because of Covid-19. Their gumbo is good, but not as good as my daddy's.