This math is wrong because tier cannot drop in TF variety and there are 15 tokens that drop in a 25man full clear.
((7*6*0.25)+(5*3*0.25)) = 14.25 TF items in a full normal 25 clear
((7*2*0.10)+(5*1*0.10)) = 1.9 TF items in a full normal 10 clear
The 25:10 TF drop ratio remains the same but your numbers were wrong.