Использование itertools.product :
from itertools import product as pd
list_result = [[''.join(k) for k in pd(*[eval(i) for i in j])] for j in list_order]
print(list_result)
Выход
[['AH1', 'AH2', 'AI1', 'AI2', 'AJ1', 'AJ2', 'AK1', 'AK2', 'AL1', 'AL2', 'BH1', 'BH2', 'BI1', 'BI2', 'BJ1', 'BJ2', 'BK1', 'BK2', 'BL1', 'BL2', 'CH1', 'CH2', 'CI1', 'CI2', 'CJ1', 'CJ2', 'CK1', 'CK2', 'CL1', 'CL2'], ['H1', 'H2', 'I1', 'I2', 'J1', 'J2', 'K1', 'K2', 'L1', 'L2']]