Ok with Tager, I realized you need two things in this match-up. 1. Her rods and 2. 6b
With 6b nerfed Tager can B sledge all day without worrying about getting countered easily. Not really. Rachel can use her rods as traps to prevent Tager from getting to her.
At the start of the match, pay attention to what Tager does. If he...
1. Sledges, use 6b>236A to lay your first rod.
2. Does nothing and starts walking back and forth(probably waiting for you to do something) do either of the following
A) Start giving pressure. If he blocks, end your blockstring with 236A. If it hits do her standard BnB
or
B) Back away and start zoning
Here is when your 6b and your lighting rods come in handy. If you start zoning Tager will use B sledge eventually. If you have rods placed between you and Tager, use 6b. If placed right, he should stop right next to one of your rods and on reaction do sword iris and it will hit. Once it hits do her standard air combo. Once he recovers in the air, land and lay down another rod, use 236A, if he uses j.2b, you'll recover in time and just IB the attack and punish. Once he lands start placing rods between you and Tager again. If he tries to B sledge again, repeat what you did from above, if you have meter, use BBL or TD(must be lvl.3 or lvl.4 for it to be worth it). Tager should not sledge at you if there are rods surrounding him or between you and him.
Once the Tager player realized this strategy, he will stop B sledging. Tager will either do the following....
1. Jump at you. If he does, your 6a and j.C will beat his j.a, j.b, j.2b, j.c. 6a will sometimes trade with his j.d though.
2. Waits for you to do a move. If this happens, go ahead and give pressure or align your lightning rods.
Hopefully with this strategy it will make Rachel vs Tager match-up a little easier for you. Good luck. I will update if there is more to this strategy.