The 1st attempt to replace the Sheridan, - the M8 Armored Gun System[0] had a similar problem - too heavy to be transported / airdropped by a C-130.
[0] https://en.wikipedia.org/wiki/M8_armored_gun_system
Much like the US Navy's LCS, both Independence and Freedom classes:
https://en.wikipedia.org/wiki/Littoral_combat_ship
Good grief!
The 1st attempt to replace the Sheridan, - the M8 Armored Gun System[0] had a similar problem - too heavy to be transported / airdropped by a C-130.
[0] https://en.wikipedia.org/wiki/M8_armored_gun_system