As a first impression, that seems pretty specious to me. I wouldn't at all describe frontal assault as being a normal chess strategy -- the most common would probably be the idea of a multi-pronged attack where your opponent cannot simultaneously defend everything, which is an equally fundamental strategy in Go, at a deeper level than "surrounding."
It's less a difference of Western and Eastern and more of a difference between Clausewitz and Sun Tzu. Clausewitz was all about maneuvering the opposing army into a decisive battle (capture the king), and although you can use clever tactics, it is ultimately a war of attrition favoring the strong (such as industrialized nation-states). Sun Tzu was about using ambiguity so that the weaker opponent has a chance of prevailing over a stronger opponent (asymmetric warfare, or "cheating"). There have been Western military commanders that have used a distinctively Sun Tzu flavor.
Even if you played chess with a multi-pronged attack, you're still ultimately gunning for the king. Your objective is absolute, and each side knows this. Your objectives within the course of a Go game is more fluid and ambiguous.
There is fluidity to objectives during a game of chess between strong players. For example:
inflicting/preventing weaknesses,
seeking/avoiding favorable exchanges,
occupying/closing important lines.
Then all such long-term considerations suddenly become irrelevant when the game descends into a tactical melee.
At any rate, I don't see how the objective of chess (checkmating the opposing king) is any more absolute or less ambiguous than the objective of go (surrounding more space than your opponent).
Depends on how you want to play. Some people try to win by a certain amount of points. Some people try to lose by a certain amount of points. Some teachers move in a way to call attention to certain shapes or tactical sequences. Sometimes you just want to stick to beautiful moves. When you throw in handicap stones, komi, and reverse komi, how much you win or lose by is arbitrary. You can win by 0.5 points, but that's largely dependent on komi you agreed to. The losing player still has half of the board.
All fluid objectives during a game of chess between strong players are still subordinate to the ultimate objective: capture the king. There's only one king on each side, so there is not much give. There are 361 empty space to choose from in Go.
There's only one king, but both sides have 15 additional pieces. One extra pawn is often enough to win, and in the majority of games between competent players one side resigns long before an actual checkmate is on the horizon.
If you want to exchange off the pieces and make a draw, you can.
If you're only interested in playing surprising/paradoxical/beautiful moves, so be it.
In go, regardless of the handicap, or whether you want to win by more or lose by less, the objective is still to surround more space than your opponent.
Like asynchrony, I don't understand this argument at all. You can play however you want in chess. It doesn't change the actual victory condition, nor does it in Go. The sub-objectives during a game of chess appear to me to be equally deep and important as the sub-objectives during a game of Go; namely, they are the whole point. Like in Go, you win by conceding some sub-objectives and pursuing others.