yes all those modes have the same notes. but that does not make them the same thing. there is more to a scale/mode than what notes it contains. most people would say someone playin in a aolion (minor) sounds different to one in c ionion (major).

so u ask why this is the case. well its because of how the notes are used. one has to emphasise different notes when playin in a aolion as aposed to c ionion.

now for instance we have a 1 4 5 progresion.
in C ionion this would be C major, F majour, G major
but in a aolion it would be A minor, D minor, E minor

these sound different. one is in a minor key and the major key although they still have the same parent key and the same notes contained in the scales one would play over them.

now if u recorded urself playing over the first progression you would probably find you could play some resonable or good sounding lead line. now if you did the same with the second progression you would also probably find you could make something nice sounding just by listenin to the music and tryin to find riffs that sound good.

but now if u analyzed the two little bits of improvisation you would probably find that ou tended to use certain notes more often in one piece than the other. this is because which notes of the scale you play mater. also if you played the same bit of improv that you played over the first progression over the second you might find it sounded alright but did not 'fit' the progression as well. this is again because it maters wat notes you chose to play.

hope this is has made it clearer. if u want more detail just ask.