This is the best I could come up with:
- Give reworked HQ glider to Commando doctrine and remove it from Vanguard.
- Add Assault Sections to Vanguard.
- Swap "Hold the Line!" from Lend Lease and Strafing Support from Vanguard.
- Give "Hold the Line!" something like a price reduction so it isn't completely useless.
I don't know if this is a terrible idea or not.
Otherwise you could just replace flamethrowers or the meh cover bonus on Mobile Assault.
Lend lease does not have hold the line special weapon does.
Lend lease an early commander that is currently everperfomring according to OP these is little reason to buff its late game also.
Finally if some abilities need to go removing Croc from one of 3 commander it is available is better choice.