I just got the Additional Companions mod installed on my PC version of Dragon Age 2 and am currently having fun putting three NPCs in my party for fits and giggles -- Meredith, Orsino, and Nathaniel Howe. Although they don't really say anything when they're in my party, it's still entertaining dragging them into situations where other NPCs like the ones particular for any quest basically ignore their presence and yet talk about mages and templars right in front of them. It can also be used as a form of revenge against Meredith and Orsino, since potentially you can take Orsino with you into the All That Remains quest and have him join you in fighting the man he was protecting who killed Hawke's mother and see just how that affects Hawke -- or alternately Meredith could be taken into Family Matter where she can see for herself how the lyrium idol has screwed up Bartrand. It's unfortunate that the Hawke-as-Meredith mod from Dragon Age Nexus doesn't work without freezing every now and then, but it's still funny to see her say to Bethany, "Don't worry! I won't let any big bad templars come and get you!" I guess the one thing I like about the Dragon Age games is the obliviousness of the NPCs and party members through the game's programming -- your Hawke or Warden could look like an abomination and they would still comment on how beautiful or handsome you are and all that.
Interestingly, this is inspiring me to write a fanfiction story where Meredith and Orsino, at the time of their deaths, are transported back into the past in their original forms about a year after the Hawke family moves into Kirkwall, and they are totally stripped of their memories and nobody in Kirkwall even recognizes who they are, but they are somehow directed to finding Hawke and joining her (yeah, Hawke is female in my story) in her adventures in order to find out what became of them and what they did to bring Kirkwall to the state it ended up in when they died.
I just got finished with my modded playthrough having Meredith and Orsino in my party and I was able to take them right through The Last Straw in either campaign, having Meredith fight against the templars and Orsino against the mages and the two of them fighting against their in-game selves, which was pretty funny and awesome especially in Meredith's case. For added fun, when my Hawke talked to in-game Meredith before the final confrontation in the templar campaign when she asked whether she could trust that "the mighty Champion of Kirkwall is not a worse threat to this city", I had my Hawke reply, "If you want to see a threat to this city, look in the mirror!" And in the templar campaign when in-game Meredith is defeated and turned into a statue, the templars bow down before Hawke with player companion Meredith and Orsino in the scene.