There are no formation rules for Augmented Lances.
You can't just put units in an Assault Lance that doesn't fit the requirements of the Assault Lance.
You can make an Assault Lance and "augment" it with two vehicles that don't follow the Assault Lance requirements, but those two vehicles are, rules-wise, not part of the Assault Lance and don't get the benefits of the Assault Lance or count as being part of the Assault Lance (for the "half the units in the Assault Lance" counting for example).