Q and D are both defensive Dmen. I highly doubt D is going to suddenly re-energize Smith's O game because of his slightly better defensive abilities.
Any D-man on this team would excel with Kronwall ad their partner. Smith is not some strange exception. Lashoff would suddenly look lightyears better with Nik.
DeKeyser is much better defensively and moves the puck well too. Lashoff doesn't have the slightest ounce of offensive ability -- that's just pure hyperbole and doesn't take into account the massive difference in skill between Smith and Lashoff.
Every time Smith and Quincey have played together, it has failed miserably as a pairing. Smith was the Wings best d-man during the Boston series and has the potential to contribute more offensively if the Wings allow him to do so, which would be wise since they got nothing from that standpoint a season ago. Restricting Smith to Quincey again isn't going to help Smith's development.
If you aren't a fan of DeKeyser with Smith, then put DeKeyser with E instead and let Smith go with Kronwall.