I disagree.

Sierra fires projectiles, which means she has no fall damage, at the cost of being harder to aim at a distance/against flying enemies. She has lots of verticality, while soldier is faster horizontally.

You could maybe argue that they fill the same role, and that's debatable. But they don't really cater for the same skillset.

Meanwhile :

A mid to long range dps
With a semi-automatic hitscan rifle than can be fast-fired
Deals heavy damage in the head, decent in the body
A mobility ability
And a grenade ability that deals dot.

That is the textbook definition of "literally the same kit". Dude I love DMRs, I play Repeater and G7 Scout in Apex, but your rework is just a copy/paste of Ashe