8650G and 8750M are built on different architecture, so there is no way that these two gfx will crossfire or forming Dual Graphics, it'll subdued to Switchable Graphics like the Intel's HD 4000 and GT 740M therefore AMD's only advantage is disappear
Here is GT 740M's specs:
http/www.notebookcheck.net/NVIDIA-GeForce-GT-740M.89900.0.html
HD 8750M's:
http/www.notebookcheck.net/NVIDIA-GeForce-GT-740M.89900.0.html
If AMD's Dual Graphics is not enabled, The only HD 8750M, if it's DDR3 version, is even below GT 640M, and the DDR5 version will do a bit better than GT 640M but will only on par w/ GT 740M DDR3. (But if Dual Graphics can be enabled it'll do slightly below GTX 760M but better than GT 750M) However, if u purchase A10's laptop u'll waste on a very good IGP (8650G) which is on par with HD 6730M DDR3 version.
Besides, Although A10 has quad-core, but Intel's i5 has better efficiency and a dual-core but 4-thread i5-3210M beats A10-5750M in CPU performance (of course i5's IGP is still far away from HD 8650G) Here is the chart:
http/community.futuremark.com/hardware/cpu (A10-5750M's score is 500 less than i5-3210m.)
P.S: Both HD 8750M and GT 740M has 128-bit memory bandwidth.
The exempt of Lenovo.com indicates that :
•AMD Radeon HD 8650G + 8570M Dual Graphics
• AMD Radeon HD 8550G + 8570M Dual Graphics
•AMD Radeon HD 8450G + 8570M Dual Graphics
But HD 8570M has only 64-bit memory bandwidth, so the "Dual Graphics" result is even worse than HD 7660G + HD 7670M though HD 8650G is 15% better than HD 7660G