I have a requirement to create XDP's and PDF based outputs and perform merging of those XDP's in real time through a workflow. Also I need an effective way of handling the versioning of those XDP files as well the fragments to be used in those forms.
So Can I achieve those absolutely without depending on AEM workbench and AEM Designer(same as ALC designer but an upgraded one).?
Is there an alternate way to achieve this without those software's.
I do not see any challenge of implementing the solution in JEE or OSGI. if you have JEE you can use workbench and automate this use case while with OSGI you can create own custom workflow. Go with the one you can easily work on and that is approved by the business needs. We support Output service and assembler on both JEE and OSGI, so decision depends on you and the Business.
Workbench and Designer are also not solely version control software, you are able to create a new version of the application not of assets alone. I haven't tried it but I would recommend having a proper naming convention of the forms that help you identify the old and newer form version or you can try using GIT,