Figured as much. Old time recipes with no understanding of cause and effect are hard to correct especially when we want one thing and to get it hurts another.
Traditionally in Eastern Europe lemon and vinegar was used to brine a lot of meats for the tangy flavour. However for the most part, that dried them out or left them tuff.
So trying to get that internal tang with a tangy sauce is my goal. Just a sauce on the roast is easy but makes for a confusing taste if you bite into the meat without any sauce. Making the meat with tang by using lemon or vinegar gives it that tang but really hard to make juicy or tender without cooking the day lights out of it.
The brine that was used is a carrot, celery root, onion, parsnip and lemon or vinegar brine.
Thinking about celery salt, onion salt, celery juice powder (expensive) etc…