If you can unlock all MkII ships without tanking your economy by building them before expanding the first time that's a definite proof that the human economy is really damn OP. It used to be that you couldn't even build a cap of bombers or frigates without tanking your starting economy so you had to expand before you had your caps built up.
Unlocking all Mark II ships and building them does tank your economy. That's why I said the early game was slower for a full-military or compromise opening as compared to a full-economy opening, and also why I prefer a compromise between full-military and full-economy openings. And if you have the patience, then no, you don't need to expand before your caps are built, though it's probably a good idea to do so. Just start out with the Mark Is and do something while your more expensive Mark IIs are building, and try your best to avoid heavy losses because you don't have the economy to replace them quickly. Once your Mark II caps are out, though, the game changes because your Mark II ships will take far lighter losses than your Mark I ships would have in the same situation - if you're careful, and avoid doing foolish things like directly challenging the special forces before you feel you have the ability to recover the losses or win that fight.
Going in for Mark II ships early on encourages a different sort of strategy than going for an economic game. With the economic game, you can afford to replace losses relatively easily and quickly, but you also have to accept much higher losses because you don't have the military strength to break through heavy resistance without sending attack waves, and you're using cheaper and weaker ships. With a purely military start, you have the ability to bring a very powerful fleet into the field and it won't take as many losses (usually - ion cannons can be a major problem, if you didn't notice them before you sent your fleet in, and minefields can be somewhat painful) as the Mark I fleet an economic opening would, because it kills enemies faster and uses tougher ships. The losses you do take, though, will take longer to replace, and if you end up losing your fleet to a poor decision, it can take a very, very long time to recover. Also, since if you open up the Mark II caps at the start of the game, once you have built your Mark I and Mark II caps, the Mark Is become relatively expendable, since they represent only a third of the fleet's strength, and are much easier to replace than the Mark II ships.
Also, I would say that blobbing isn't a strategic problem - in choosing to keep your mobile forces in one group, you've lost a bit of flexibility in exchange for local superiority, and you're relying on the defenses that you've built in order to protect your worlds (or at least delay attackers long enough for the fleet to come to the rescue). Blobbing is tactically uninteresting, but it is a choice you make on a strategic level - do you think that your defenses can hold well enough that you can take your full fleet with you everywhere you go? If yes, then the next question is whether you want to strike several targets or only one, and if you want to strike several, do you want to do so simultaneously or sequentially? Do you want to bait off the special forces (assuming they aren't crippled yet), or do you think that you'll have enough time to finish what you came to do before the special forces arrive, or that you'll bring enough firepower to accomplish your goal even if the special forces interrupt you?
I would say that the main thing encouraging strategic blobbing is more that controlling forces on separate planets is relatively difficult, rather than that it is by far the best thing to do.
Hang on.
Isn't the dominance of "blobbing" sort of implied by Lanchester's laws?
In many other RTSs, this is averted by making it such that you opponent can take out key structures before you have enough time to "blob", thus pressuring you to do the same.
Although the AI could be more aggressive more often to simulate that, it can't go too far or else it would violate the "player controls the tempo" design goal of the game.
I kind of feel like the threatfleet behavior is simulating this somewhat - if you allow threat to build up, doesn't it attack you if you move enough of your strength elsewhere for the AI to decide that it's time to go smash the player's world(s)? Although, the worlds it chooses to attack probably aren't the worlds that I consider particularly important, since a world important to me would be given as sizeable a defense force as I could afford to give it. Still, if I have few enough worlds, losing the energy collector could be painful.
