If the Hostas had problems with too much sun, the hydrangea leaves may too. I would place them in the shade garden if the shade is bright shade.

I should clarify that some of the hosta burned and didn't do well. They were the blue and variegated varieties.

The greens did far better and are doing well this year with a cooler summer. I'm splitting them and moving them to another bed, since the majority of the bed has already been moved.

Little Lime is a paniculata type hydrangea, prefers full sun, which is different from the big leaf hydrageas such as endless summer (with big pink or blue flowers) which prefer moisture and shade locations). I have several of the taller version Limelight, planted in full sun locations. They perform very well, bloom for a long time with many large flowers. They are not picky about soil. But amending your soil with some good top or garden soil will help the roots established. After the first year, you typically do not need to water them unless during extremely dry and hot conditions.

My neighbor planted a few little limelights in a place where it only gets more sun, they do not bloom very well. So she moved them to a full sun location last year and that made a big difference.

Good luck.