1. Captain Britain's strength would be too overwhelming for Commando to handle. Captain Britain can currently lift 90 tons at peak condition, his powers used to be dependent on his costume however currently they depend much more on his level of confidence (similarly to Marvel's Gladiator), the more confident he is the stronger he becomes and the less susceptible to damage he becomes.
2. Captain Britain is also faster than Captain Commando and has the ability of flight. Captain Britain's speed is sufficient enough to surpass the Speed of Sound, 770 miles per hour. The force field that grants him his superhuman durability enables him to withstand enables him to withstand the rigors of traveling at such high velocities would have on human tissue without harm as well as allowing him to breathe normally.
3. While in his costume, Captain Britain's body is surrounded by an invisible force field that renders him highly resistance to physical damage. The field allows him to sustain powerful energy blasts, great impact forces such as bazooka shells or being repeatedly struck by superhumanly strong opponents, extreme temperatures and falls from great heights without being injured.
4. His superhuman stamina produces less fatigue poisons than the regular human being and he is able to exert himself in intense physical activity for over 48 hours before his body begins to produce fatigue poisons and impacts his body.
5. Captain Britain is an excellent armed and unarmed combatant and has incredible skills in hand to hand combat. He also has a very limited ability to manipulate magic for certain effects.