@ It-Ogo: I have to disagree here: It is synergy and a well developed civ which is more or less done.
When those coves were buildable next to one another it was clearly an exploit but the pillaging of coves makes it possible for Lanun to play out their strength on maps with a bit less water than continents. Do you really consider that a bad thing? (Remember the new way Motherlode works and see that the path done by design has gone just that way to make the map addapt to the civ / player and not the other way around.)
Also getting 4 Coves maximum (3 are normal in fatcross and only 2 in Freshwater is the rule) is not such a big deal. The difference between a normal freshwater lake and a freshwater cove is huge.
Sure Freshwater + Lighthouses (which are not cheap btw. and absoloutely require Ocean which whould be much harder to get if you render coves nonpillagable) is nice. But not any more Powerful than comparable strengths of other terrain dependant-civs. (which save for dwarves all require quite some micromanagement.).
Micromanagement if it makes sense for the game can have its merits. (as oposed to uneeded annoyances which make the game less from any point of view and for any playstyle)
Overbalancing everything all the time whould kill the game. Thats why i really dislike the direction the discussion in the balancing thread is going.
There competatively-oriented players argue on behalf of a balance of equilibrium between civs.
The result of this are complete fun-killers like the over-nerf that has been forced down the throat of grigori players.
Sure they are still playable and offer a fast rushing-option. But fun playing them has largely diminished by the qaudruplenerf (merging Sorcery and summoning has hit them, as has changing the tech-tree and Bulbpath as has barring Honor and Deception as has denial of Druids.).
Taken alone some of those changes makes sense (especially the merge of sorcery and summoning since that has a chance to make the game more fun once the magic-system is finished and rounded. Also its more easy for newcommers) but taken together they take the fun away from that civ (and some dont even make any sense flavorwise like barring of Honor and Deception. Where if anything the problem lies with the broken way CoE is spread not the Grigori founding them.) and make it much more onedimensional to play them.
Whereas the FFH-Team has more than once stated clearly that the way FFH is designed follows guidlines of nonsymetry (which runs counter to comparable balancing), replayability by different ways each civ plays (which at least doesn't make comparable balancing not easier) and choice of good options where only the nonuse of the other options is the balancing-factor (which also is a different angle to balance instead of comparing between options and making them equal in strength.).
So if anything the other nonfinished civs like doviello are to weak / not outstanding enough and not lanun or terraforming to strong. Balancing can go both ways after all.
@ JanusTalaiini: Balance is only a small! tool for fun here not more. Let alone a major guidline.
If you want balance-equilibrium, modmod it. (which whould indeed make sense for competative multiplayer since i can accept that thats a very fun way to play as well. But it takes a whole different aproach by design to balance a game for that kind of players. Also Kael has made it easy to modmod his game.). But any argument about cheating and comparing using a games features as intended! with using Worldbuilder ignores the base guidlines of FFH 2 design which have made the game as greath as it is.
So please leave the single-player community alone with those unbalance-whining and cheat calling and destruction of a perfectly fun game for the sake of something which is completely! valueless in singleplayer (equilibrium-balancing).
The only real problems to FFH2 balancing stem from options which overshadow everything else so hugely that anything else becomes a de-facto-nonoption (like meteor-shower has done to the magic-system which made people ask why to pick anything besides fire. Now perhaps Mind more or less leads the Spheres but its fine imo since it doesn't render most other spheres nonworthy or replaces a big part of them. The old charm person also has been an example of that, as has the old blinding light. Entangle is still way to weak and needs a beef-up in comparison) and clear exploits which distort features in an unintended way like building coves next to one another (or once the ability of ganovan to teach priests to cast arcane spells which has been reintroduced unintendedly in 0.30. and left in for the sake of fun and testing. That should be a clear indication how unimportant relative balancing is as of now.).
In fact if i whould follow that kind of argument turning off barbs, unique features and playing without AI Civs or at quick Gamespeed (which should be necessary for a more or less fair and fun competative multiplayer game) or playing with unrestricted leaders in Multiplayer is cheating and breaking the game / comparable to using the world builder since its clearly not the way FFH2 is meant to be played.
(Just as an example that that kind of arguments are completely misplaced and can be put both ways. Ironically your side of the argument is weaker here since FFH2 is not designed for Multiplayer as a major focus for design. But i whouldnt want to indulge extensively in that kind of discussion since i consider both camps preferences as completely valid and understandable

. Thanks to the modability its also no real problem to achieve both. The main game for Singleplayer with Modmods for competative Multiplayer.)
So please refrain from that kind of nitpicking.
And also most importantly: The game is not finished. So any balancing discussions about small differences is mostly moot since you cannot sensibly compare a finished feature (Like Elven Forest-Economy) with an completely unfinished one (Like AI for Example).
Also makes some unabalances ok to test for a time to see how it plays out and what is fun / hitting the right point. (so it can even be good to the develepment of the game to have some imbalances.)
Fine-Tuning of balance will surely (if at all necessary) be done at the end of Shadow-Phase or during Ice phase but now its time for beta-work.
To answer your last question: Not needed if it doesn't make anything else completely useless in all fields (best options in one field of the game are clearly ok in single player imo. In multiplayer they do lead to problems.) or is a clear unintended exploit and makes the game more fun to play.