on the subject of "forced" objectives:
"forced" objectives are inherent in all strategy games, but whether they are "FUN" is wholly dependent on how they are set up
take for example a game with episodic battles that you "can't" avoid (i can't actually think of any outside RTS tutorial/early RTS campaigns)
there is no decisions for the player to make, they must attack the enemy head on to win
The great examples (purely in the realm of RTS/civ games), they have multiple paths to solve a problem : you have an army, an enemy army is fortified on a hill, to win you can just as easily walk around the enemy army (totally avoiding them), besiege the base (starve them out), use diplomacy, pound it with artillery, harras, raid, crush them economically without ever firing a single shot, ect...
the "good" examples of this you can use artillery, and draw your enemy out so that they can be sniped, or flank them and destroy the line that way, or you can harass and repair cycle until you win or... you get the picture, there are more ways than one to solve the problem
(in SS this is impossible... the UI and the AI simply do not support tactics)
in the "bad" example you are forced to ram your army head on into the enemy army with no strategy whatsoever (and minimal tactics)
(this is what SS currently is from a strategy point of view)
SS falls heavily into the "bad" side of staged battle, it is why your aim in any battle is to "out-tank" your enemy rather than "out-smart".
The key to making losses “acceptable” is to give the player the tools to decide what losses they want to take, and how they will go about taking them, like the sacrificial pawn trades in chess, you do not want to lose a pawn, but to win you must for the greater good. The death of the “pawn” has meaning.
In SS the death of a “pawn” is usually senseless and out of your control, thus losing the pawn feels like a loss of control for the player, and makes the gameplay experience “bad”
TL:DR -- i am not arguing against the "combat model" of SS, but the strategic value, and the potential meaningfull choices players can make in(and outside) battle
(curently verry little to none can be made, and the AI does not effectively execute the choices that are made)
something to look at would actually be the "Mount & Blade" series
Spoiler
its closer to the strategic premise (or lack there of) that SS uses
but it has several key differences
1) it is purely a 1st person combat simulator, there is no real importance placed on the "fleet"
2) it does not give "detailed" control to the player, only a general attack/retreat
3) units are disposable, if you lose half your army, it won't take you hours to rebuild it, all you need is the nearest town
4) risk is directly proportional to reward, you take on a late game army and win-> you get enough gear to build a new army of that class
5) the AI in warband (generally) does not QWOP, it is limited, but on par with the player character's level of ability with the same gear