Life Is About Balance
Karl started with the easier parts, the increase in the quality of the two spaces, and the addition of simple grass to the ground. Instead of the short grass that Hawk liked, it was longer grass. Rae liked to hide in the long grass, and Thor liked the way that it tickled his belly scales.
No judgment.
Then Karl left Thor's mostly empty, as all the other plants in the space were going to be food products. The power density of both was increased evenly at the start, but after a few hours, Karl began to experiment and found that Rae actually required much more power in her space to relieve the strain on his mind.
Her species was the more powerful of the two, and her power was growing more rapidly as well. The side effects of that could be problematic later, but the short-term benefits would be huge.