B777 PACK MEL & Weight Penalty

[agg_karan]

Hello all,
This is a regarding B777 300ER/200LR

Doubt -

MEL (21-51-01)
on PACK L OR R (I understand every operator will have slightly different MEL based on their a/c specifications)

One step in the (O) ops PROC mentions -
REDUCE PERF LIMITED WEIGHTS

for TAKEOFF/LDG 300ER(GE90-115B) - 5262 Kgs
ENROUTE - no penalty

for TAKEOFF/LDG 200LR(GE90-100series) - 6713 Kgs
ENROUTE - no penalty

Q1) assuming PACK EXTRACTS AIR from the ENG, one pack now under MEL, and 'lesser' load on the ENGINE, why is there a higher weight penalty (at all) for TAKEOFF/LDG ? (Emphasize PERF LIMITED WEIGHTS & not structural or Landing weight restricted).

Q2) What is the reason behind the 200 LR Having a weight penalty of 1.6 T more than 300ER. (I know it's a diff engine)

Apologies if I have missed anything too obvious.

Thanx
Regards.