Short rise bottom step or platform
If I understand the question correctly, then steps should always be a uniform height.  The 9 1/2" rise at the bottom of a series of 7 1/2" rises is definitely bad.

Adding a 2" platform on the ground below the step to even out the overall step size is a great idea.  I'd suggest you make the platform be large - something like 2 feet deep and 6" wider on each side than the step itself.  That will give it a clear, distinct landing feel and be much safer than having that 9 1/2" drop at the end.

If you can't do that, however, then making the new bottom step be only 2 1/2" above ground is better than the 9 1/2" you have now.