To achieve load sharing in a planetary, often either, or both, the sun and ring gear are allowed to freely move radially. For example, the ring gear can be mounted on a splined connection, which is then connected to ground.
In two stages of planetary gearing, if the carrier of one stage is radially positioned by the sun and ring gear, and in the next stage, if the sun gear is located by the planet gears, you need no radial restraint of the sun/carrier connecting shaft. That is what I meant by "float".
I have been getting a real itch to design a 20 kW wind turbine, and have started designing one. Maybe eng-tips needs a wind turbine forum.