As you said and as we all know there are basically 3 types of birds , light , medium and heavy .. BD-AF already have Yak-130 (advance lift trainer ) so they don't need another light bird JF-17 , they just have to increase numbers of Yak-130 ,,,,,
For Medium category , they think they cannot trust China , fair enough , but going for gripen is as dangerous as going for China's J-10 , simply because very few operators of Gripen so very less chances of Sp-Parts if sanctioned ,,, better option is F-16s simply because of Sp-Parts (so many countries using F-16s and Keep in mind Turkey) ..
Foe heavy they can chose any from EFT , Rafale , SU-35 (all three have their own advantages and dis-advantages and BD have to deal with them) .