consider the possibilities of using the OT as a performance hub and the many ways you could put its crossfader to use, not to mention its many additional fx type options and LFOs. resampling would be simple on both, but on the OT you’d have the option to timestretch. you wouldn’t need a mixer either.
then check out this thread on combining OT and DN, and consider whether any of these options sound enticing. ask yourself whether any of them would translate interestingly to OT+DN.
…for me the choice would be easy, so maybe ask yourself what you’d gain from having two Digitakts. no learning curve? slightly smaller footprint?