Connecting Dragonfly 1.2 to Fiio E12 to AKG m220

If I have at my house a laptop and a Minix NEO u1 streamer, and i want to hear high quality sound (let's say using TIDAL service or apple music) through my AKG m220 headphone (it's the same as the AKG K240 headphone) and my Logiteck X230 amplified computer speakers. 
The question is- do the Dragonfly 1.2 enough for that? I have the opportunity to get for a good price the Fiio E12 headphone amplifier, so I can connect the Dragonfly 1.2 to the computer for instance, and with an interconnection cable connect it to the E12 amp, and then from the E12 connect it to the M220 headphone. The thing is there is an option in the dragonfly to use it only as a DAC and "shutdown" the internal amp . What do you think about this arrangement? or should I drop the E12 and don't buy it and use only the dragonfly 1.2 with the AKG headphone and that's it? this question is also regarding the minix streamer (it can support USB DAC) .
What about the Logiteck X230 amplified computer spearkers? what should be the arrangement for that with the above devices?
Hi Azrco - I run a similar set up (I think) for headphone listening from a MacBook Air for Spotify or ripped CDs.  I have AKG K550s and Senn HD600 'phones.  For the more efficient AKGs, the Dragonfly v1.2 alone is adequate.  It will even drive the less efficient Senns.  I do prefer using a headphone amp for either, though.  My recollection is I checked before buying and the Schiit Asgard 2 that I purchased can handle the input voltage supplied by the Dragonfly.  I plug the DF into the computer and use a mini pin to RCA splitter + IC cable from DF into the Asgard.  I don't do anything to deactivate the DF's amp.  I plug the 'phones into the Asgard.  Mostly I leave the Dragonfly volume on the MBA at 100% (iTunes/BitPerfect volume also at 100%) and control listening volume via the Asgard. 

In the same room, I have desktop AudioEngine A5 powered speakers.  I plug a mini-pin equipped cable from the A5 amp into the Dragonfly.  It sounds great.  

So, my input to you is the Dragonfly will probably work with your proposed headphone amp but since I can't speak about your E12 amp specifically, look at the specs for it and see what they list for input voltage range vs what is cited as output from the Dragonfly.  I do think a separate headphone amp will give you more flexibility down the road in terms of headphones you can use.  It might even provide better sound.  

Good luck.