Bismillah. This is a Q&A session I had with an Ahrar Fighter on several important questions. I will try to present to you the reasoning Behind Ahrar spearheading the formation of the Islamic Front. If any Ahrar Fighter reads this and sees something incorrect pls correct me.

Ahrar views that they alone, nor can they and Nusra, nor can they and all 'salafi-jihadi' groups form a functioning state to rule Al Sham By sharia. Infact they believe that the only way to form a functioning Islamic state without massive bloodshed and civil war in a post  Assad environment is if all or most of the groups unite under the common goal of establish the law of Allah(swt). This is in short the reason Ahrar joined the Islamic Front and infact seeks greater union including more groups. If you read the Charter of the Islamic Front you can Clearly see Ahrars hallmark all over it as if an Ahrar Shar3i wrote it. The key points including:

1) sharia is the ONLY law
2) complete Rejection of democracy, secularism, parliaments.
3) Muhajireen are our brothers who will be treated just as an other shami.
4) Complete Independence from foreign nations (while Stressing they don't seek enemies with them)
Etc.

Reading the Charter it would be very hard, for Even an IS supporter to find serious flaws or sharia violations in it even if they may disagree.

Keep in mind Ahrar joined and formed the Islamic front, with strict adherence to the charter, meaning any groups whether Fsa or MB who sought to join must accept this charter. 

Speaking to an Ahrar source this is how he put it "we should try to get the groups to come to the project of an Islamic state and not push Them away to foriegn projects. We can't isolate ourselves as the 'salafi-jihadis/Manhaji's' and not try to include the other Islamic groups (ikhwanis, salafis, etc) under a Islamic oriented project". This is in short the reason and how the Islamic front was formed.

Now allow me If I may to give my opinion. Ahrar made an Ijtihad and If they are correct they get the reward doubled, if they are mistaken they get 1 reward. Personally although the intentions behind the Islamic front were good, I disagree, for all the reasons we see today. Islamic front Didn't fully function as 1 body because of the great difference in views.

Another point that is important to mention is this. When ISIS Found that their was nothing concretely in violation of the sharia in The charter (as Ahrar intended), ISIS focused on the inclusion of Zahran Alloush in the front and totally ignored the foundation of the front. They took the ALLEGED Alloush ties to KSA, and labeled the Entire Islamic front, as Al Jabha Al saluliyah (the (Al) Salul front (ksa derogatory term). ISIS even made a famous nasheed sung by  Nimr AlThiyabi titled "الجبهة اللي بها علوش مخذولة" where IF&JN were cursed

The true reason IS made takfeer on IF is because of this (hence the term Saluli front), suddenly this was proof for them that the Islamic Front and all those groups in it are Apostates kuffar whose blood and wealth is halal. And this is the reason IS made takfeer on JN, for Allying with the 'Saluli Front' as they put it against them. Hence the blood and wealth of JN became Halal. 'nasheed' and you will see how this evil thinking began.

Listen to the before mentioned.

By @Emirate_sham أبو سمية الخالدي