A simple high-power thin-disk pumping configuration using a radiation combination of four commercially available laser–diode stacks is introduced. Two setup modifications are presented to compensate the nonsuitable shape of the pumping spot arising from low beam quality in our combination method. The effects of setup modifications on pumping spot shapes are confirmed by ray tracing simulations using Trace-pro™ software. All setups are arranged in the laboratory, and the experimental measurements show pumping spots improvements on the disk due to modifications in agreement with simulation results. Output power measurements show that by adapting the pumping spot size to the disk cooling capacity the modified setups can deliver higher output powers and efficiencies. Furthermore, the modifications reduce the laser threshold and improve output laser beam quality. Hence, the modifications make the simple four laser–diodes beam combination applicable for thin-disk laser pumping.