16 year olds marrying is not the worst thing in the world.
If they hold the age at 16 and there is no forced marriage, I don’t see the problem.
This being a Muslim country, I suppose there could be twelve year old sixteen year olds and the family arranging the marriage without much concern for the wishes of the bride.
So it would not have been the worst thing in the world if Mahomet had only waited until Aisha was 16, then.