If you use Window|New window this will open a new window and you can select a different sheet in it. You can then use the Restore down button at the top right of the window and drag the sides to make the window smaller. Do this with the second window and then arrange them side by side.
In principle you could do this with all 6 sheets but I think that would be messy.
Personally, to compare 6 sheets I would print them out.