The heavy booster can be the same, and any mission beyond LEO will require refuelling, and the tankers can be standardised. I think the terminal mission compon

The heavy booster can be the same, and any mission beyond LEO will require refuelling, and the tankers can be standardised. I think the terminal mission component is always going to have to be customised to the mission type. A Lunar lander and Mars lander are very different beasts, but even just basing those on a basic Starship hull is a big win over completely custom from scratch systems such as the Blue Origin lunar lander.