Congratulations, you just extolled doing 4 less damage than Mortifiers in the shooting phase* (6 if you aren't in half-range) for 50-65 more points, an action, Divine Guidance, and
a command point. This is irrespective of the Argent Shroud reroll since that only equates to a 2/9 chance of forcing another save.
4 Mortifiers are 240 points with 8 BS3 heavy bolters. 3 Paragons + a minimum Dialogus is 290 points.
Mortifiers average 12 damage to a unit of Marines. Paragons with your listed buffs except for a Canoness deal 8 damage, or 6 damage outside half range. A Canoness only adds one additional failed save to the totals, bringing them to within 2D within half range, or within 4D of Mortifiers outside half range. Vs. T5 3+, Mortifiers do equal damage to Paragons once the Paragons are buffed and inside half range.
As for saves, with the Hymn active Paragons take as much damage on average as Mortifiers after their FNP when shot by dark lances and multimeltas. The Mortifier, however, will generally survive an attack from a Dark Lance with 1-2W remaining (~26% chance) and 93% chance of surviving a Dark Lance at all (failed hit, failed wound, FNP reduces damage below 5). 55% of the time, the Dark Lance attack doesn't damage the Mortifier. A Paragon has a 69% chance of taking no damage from a Dark Lance, but if the SoF save fails there's only a 1 in 3 chance the Paragon survives. 20% of Dark Lance attacks will destroy a 5++ Paragon. 7% of Dark Lance attacks destroy a Mortifier.
I'll math how both stand up again multimeltas later. Don't have a lot of time right now and this post went longer than I anticipated.
* Numbers are purely for heavy bolters. Storm bolters will follow later, though the different ranges will require 4 sets of data points.
Edited by taikishi, 14 June 2021 - 03:49 PM.