If you happen to have five Fire SR Disaster Lances and they're there because they need to be there, aka you you didn't play from the start so you don't HAVE better... then absolutely. The Phantom Lance has Assault(++)/Defender(++) on it, and that alone means that as soon as you have the five other Spears, the Phantom Lance goes into your Grid.
However, it might not be worth it to downgrade anything to get a Phantom weapon into your Grid. As in, if you have FOUR SR Lances in there, should you swap one SSR out for a fifth and another SSR out for a Phantom? That... that's hard to tell. Maybe? I have made a pain in the ass to use advanced calculator which could tell you if that's a good idea or not.Unless you need Kishar to live, and with that team I doubt it, swap her out. Otherwise Acala, as Acala works great from the backrow (if somebody dies, it tends to be during Rage, so a Rage punisher works great, plus you don't need to carry Acala around until Rage happens).