Hydrolox-Full Flow Staged-Alpha
size 1, throat 1, vacuum thrust 4849 kN, weight 7460 kg
size 1.92, throat 0.5, vacuum thrust 4808 kN, weight 7500 kg
size ratio 1:1.92 means volume ratio 1:7.078
solid-booster-echo
size 0.8, throat 1, vacuum thrust 2163 kN, weight 402 kg
size 1.5, throat 0.51, vacuum thrust 2160 kN, weight 523 kg
size ratio 1:1.875 means volume ratio 1:6.592
While their visual size and volume are so different, adjusting throat makes their thrust and weight similar,
it doesn't seem it's technically possible in reality, especially when the throat looks so small compared to pump and the entire nozzle
even if throat enlarged from 0.5 to 1, that's only 4x area scaling, the pump only needs to run faster rather than becoming much bigger and heavier