Your MOTU 828mkII can generate SMPTE timecode using the MOTU SMPTE console. Check out chapter 14 - p103 of the
manual so if you have MOTU AudioDesk or Digital Performer, you could play your 5 tracks, generate timecode from the sequencer and sync your video in Arena that way.
Another approach would be to generate SMTPE directly from Qlab and sync your audio files using the
timecode trigger function. I personally use
Soundflower (2Ch) channel 2 and
Loopback to both route SMPTE back to Qlab and also as a line out signal on the Right channel.
Edit: If you don't own Loopback and don't want to invest $99, you could create two SMPTE cue in Qlab, (one soundflower and one built in output), nest them in a group and choose "Start all children simultaneously".
Edit #2: I always forget about MTC! Instead of using SMPTE to control your audio files in Qlab, you could create one MTC cue and one SMPTE cue in Qlab, (MTC on the built-in IAC bus and SMPTE on the built-in output), nest them in a group and choose "Start all children simultaneously".