The northwest region of the map is completely empty, and needs something. I suggest a new gang turf. It would be located in Oreokastro, and its gang benefit could be increased drug runner mission payouts (boat & plane). If the Turf had a drug dealer, then it would only be useful for crank, and very few people do crank. Instead of a Turf Drug Dealer, I suggest a Turf Wong Trader. You can sell anything that you can usually sell to Wong's Food and Liquor to it. This would be great for scotch, moonshine, etc. The only problem with this is that it would not make sense to have a cut taken from the cartel when selling at your own turf. Therefore, your gang would only be able to access the Turf Wong Trader if you also had ownership of Wong Triad. This fits perfectly, since one of the two spawn locations for Wong Triad is relatively close to Oreokastro.
https://imgur.com/a/kEeyP1V