If I understand what you're asking, you're suggesting an inefficient solution. I don't have time to write a detailed response right now but I'll try to do so this weekend.

It sounds like you're suggesting a lunar lander capable of flying directly back to the Earth. This is similar to the Earth Orbit Rendevous proposal that was in vogue before the more efficient Lunar Orbit Rendevous concept was developed.

The key to making a practical lunar lander is controlling weight. If you have a lunar lander that includes all of the fuel necessary for achieving lunar escape velocity (which is closer to 10,000 KM/hr, if memory serves), then you're carrying a low of dead weight to the surface for the landing. You're also carrying the dead weight of the heat shield, a stronger than necessary structure to withstand reentry aerodynamic stresses, and the parachute system. All of that can add several thousand kilograms to the ascent vehicle mass, which in turn means the descent segment will require a lot more fuel. This is based on the assumption that you aren't able to generate the fuel for the return flight from lunar materials. Until we know for certain what lies at the lunar poles, that seems a safe assumption.

As I've written before, weight is the enemy of all things good in aerospace vehicles. Weight snowballs quickly, so the additional mass required for the return flight means additional mass for the descent flight. That in turn means additional mass for the lunar orbit insertion (unless you're talking about a direct descent) and that means you'll need a lot more propellant to accelerate everything to achieve Earth escape velocity.

If memory serves, the Earth Orbit Rendevous scheme would've required something like 2 Saturn V flights to send up the lander and necessary propellant and a Saturn IB flight to carry up the crew. Instead, LOR allowed them to do the entire mission with a single Saturn V.

There is a better way. I'll try to write about it this weekend.