I'm not too worried. If it turns out that pillaging rewards are too high, they'll tone them down in a future patch. At least it's encouraging that they are having a look at how people are playing the game and seeing that pillaging is a mechanism that is pretty underwhelming. And if not, a mod will probably be able to adjust them properly.
From what I understood, they're mostly going to scale them up as the game progresses, so that the rewards keep up with say science and culture costs. Right now 25 science in the second half of the game is not that relevant.
Remember the neighborhood gold thing? I can usually get ~20,000 neighborhood gold in the previous patch. And many people complain that this is imbalanced.
Then the developers made a change,
they doubled the neighborhood gold! Now at least my games, are half about researching quick to neighborhoods, and gold.
Remember the chop thing? Chopping was the main source of production in vanilla games. And many people complain that this is imbalanced.
Then the developers made a change,
they maintain the already-imbalanced chop yield, and introduced Magnus to add a further +50% on top of it! Now at least my games, are half about quick getting Magnus, and chop chop chop.
Remember the goddess of harvest thing? Goddest of harvest outperforms the sum of all other pathenons in vanilla games. And many people complain that this is imbalanced.
Then the developers made a change,
they introduced Monumentalism and Magnus! Making this pathenon much more imbalanced! (Though players can seldom get it since it is the 1st choice of AI pathenon.)
What the developers do are not balancing the game, instead, they make the strong stronger, and the weak more useless.
I expect GS is all about pillage.