Pershing and Jackson coming from same tier would lead us to the most scary axis dream, Pershing+Jackson combo.
I doon't want to look so stubborn but you are not right. You can allways mitigate problems through price. Think about it:
1. you will need T4 aka Major;
2. you will need to pay for unlock the Pershing (aka x fuel and x manpower OR x manpower);
3. you will need to pay to build the pershing (aka x fuel and x manpower)
I don't really think you will be able to build so many Jaksons and Pershings that way. Not in 1v1s or 2v2s and reaaaly late in 3v3s and 4v4s when OKW will have its KTs/Panthers and Ostheer its Tigers/Panthers on the field.