It isn't that it can't "handle" the cards, that isn't what I am saying. I am telling the OP that BOTH the CPU is a issue AS well as the choice of cards because the cards themselves can't provide "current generation games at high setting" as the OP is setting as the standard.
For example WatchDogs
http://www.techspot.com/review/827-watch-dogs-benchmarks/page4.html Note all the cards he picks best FPS for HIGH settings is 40s, whcih means when it get's 'intense' he would be dropping to 20s or lower. CPU wise here agian
http://www.techspot.com/review/827-watch-dogs-benchmarks/page5.html note only i3-3xxx or 4xxx can achieve but again only with high end video card to offset the graphics load. Here is a actual test of the OPs CPU and is in 20s!
http://www.tomshardware.com/reviews/watch-dogs-pc-performance,3833-8.html
BF4 http://www.bf4blog.com/battlefield-4-retail-gpu-cpu-benchmarks/ Easily see how low performance any of his GPUs would be, and the CPu specifically gets maxed out (see the 90+% CPU usage) and overall causes again terribel performance. And AGAIN
http://www.techspot.com/review/734-battlefield-4-benchmarks/page2.html (not the lowest score IS a 560TI the OP is wanting NON-TI!)
http://www.techspot.com/review/734-battlefield-4-benchmarks/page6.html and again once below a i3-3220 your dropping off a cliff, and that is when it is paired with a R9 290X! Again combined with the GPU choices only makes the performance in the teens to MAYBE 20s even if dropped down to Medium still wouldn't double his rates (20s to 40s).
As for the 750Ti
http://www.bit-tech.net/hardware/graphics/2014/02/18/nvidia-geforce-gtx-750-ti-review/5 again same things.
Honestly assessing OPs choices suggest he/she is trying to do a 'under $100' upgrade to achieve "current generation games at high setting" which isn't doable. Hence rather then blow his/her bubble and honestly tell them they need nothing less then a system costing around $1000 or better (To do WatchDog, BF4, BF:HL, COD:AW, The Division, etc. all just 'saw at E3') I offered the suggestion in his/her price range: GET A CONSOLE.