You'll need to cheat to get two strongholds, though.
This allows for all sorts of fixes that cannot be achieved with an. esp file, the Morrowind Code Patch fixes engine bugs by patching the Morrowind.exe. Unlike the patch above, which fixes things like quest bugs, dialogue typos, floating rocks, etc. It is, however, impossible to join both House Redoran and House Telvanni without cheating or modding. Morrowind Code Patch: Now this is something else. Odirniran/Telvanni at Odirniran, where being in both Telvanni and Hlaalu you'll have to kill everyone there also Rethan Manor will appear and it is required that you kill the owner of it. If you check then, you'll see that you are a Hireling in House Hlaalu and can do the quests, although some conflict, like e.g. Followed by a raise in Hlaalu rank which can be repeated for more free promotions. Since you already have some agreement with Orvas Dren, I will name you the new Grandmaster of House Hlaalu. You could not hold that rank if Ovas Dren did not wish it. If you join House Telvanni or House Redoran first, then slay Orvas Dren or convince him to allow you to become Hlaalu Hortator (you will do this for the Main Quest), you'll be able to speak with Duke Vedam Dren about the Camonna Tong, and receive the message, Yes, I heard that you were the Hortator of House Hlaalu. It's actually possible to be a member of House Hlaalu and one other house at the same time.