This topic looks a bit like Flettner balloon and VAWT side by side but there are significant differences because of the use of Savonius rotor kites that generate torque and can flight alone by themselves. Both Savonius and Darrieus rotors are VAWT. So I think this topic could allow to clarify the set of possibilities in this field.
Preprint: Savonius and Darrieus VAWT side by side AWES, DOI: 10.13140/RG.2.2.32340.62088
Savonius kite VAWT generate both torque and lift by Magnus effect. Darrieus VAWT generate only torque but sweep a larger wind area and are more efficient.
As the VAWT shown here sweeps a large area, the Savonius rotors may need to be longer in order to counter the drag generated by the VAWT. The sole purpose of rope drives is to transmit torque from the combined VAWT and Savonius rotors. The TSR of a Savonius kite can be estimated at 1, and that of a VAWT at 3, perhaps more. Their respective diameters are adjusted, just like the Sharp balloons with their VAWT. The discs are of a much smaller diameter than that of the VAWT which then includes amounts supporting the blades. A lattice of inflatable bars can increase the rigidity of the VAWT. Usually a Savonius turbine is installed inside a Darrieus turbine to help starting. But such a disposition would destroy the lift of a Savonius turbine settled horizontally as shown with tests using a Sharp rotor inside the Darrieus VAWT. It is the reason why Savonius rotors are settled externally to the main Darrieus VAWT.
During very old tests I noticed that Savonius kites had a good torque, being able to rotate a Flettner rotor of same dimensions, the whole flying. The same applied for Darrieus VAWT with the difference that the Magnus cylinder lifted frankly but the whole thing was unbalanced and did not really fly because the Darrieus VAWT does not generate Magnus effect.
It looks that both Savonius and Darrieus VAWT could lead to a successful combination, the Savonius VAWT being settled at each side of the Darrieus VAWT because they generate lift by Magnus effect, in addition to the high torque helping start.
All parts are inflatable except for the fabrics inside Savonius kites. A gas lighter than air can fill the inflatable parts. For this arrangement, the elements are light, and the part lighter than air can be reduced or even perhaps eliminated.
These devices can also be stacked horizontally.
Caption
Savonius rotor kites have three advantages: they are self-rotating, generate torque, and can fly like kites without additional lighter-than-air gas under certain stability conditions. Their low TSR is not a major disadvantage because, just like the Flettner rotors (under penalty of excessive energy consumption for rotation), it must match the angular speed of the main Darrieus VAWT, and therefore be of a smaller diameter.