Most Paladin openings seem mana and/or action starved. In fact siren seems like that as well.
Even the cheaper ones still require a lot of mana spending on Turns 2-3 and don't give you much defensive or immediate offensive options.
Banner is weird. You can cast it as a "come to me and destroy it or I will get crazy value later in the game," but most pallies that don't use temple want to win in the 6-12 round range.
I also noticed that with pally unless you go Temple, you will want to go all out aggressive bc if you don't you will just generally get overrun in the late game or super defensive bc you get rushed. Not much middle ground.
It's hard to know when to cast the creatures with banner vs hardcast especially.
If we go through his creature selection
Red helm: really good overall creature, but not especially vs flyers as you can potentially never get the +2 melee.
White Cloak Knight: Underated. Pretty good stats and his special ability is amazing. Put asyra's touch on him and you'll be healing anyway. Won't die anytime soon.
Cassiel: Really good, lets the pally spend actions attacking or whatever he needs to do. Run her in almost every pally, but it depends on if you will have the action and if you have enough spells she can cast to get good use out of her.
Blue Knight: Really good, but personally I do not like him. Don't run him unless you plan to build your entire book around him.
Ehren: Again really good, but he slows you down to much imo. I've found he is solid in Temple Pallies, but in SWAT ones, he simply slows you down to much imo. He is best cast when you have other threats on the board that let you spend actions to heal him.
Angels: Guarding one is amazing really good creature as everyone knows. Gray angel is HIGHLY underated. Solid attack and stats and if they choose to focus her, just use her innate healing.
Vanguard: Good and cheap, very nice vs rushes. Hit them and he can still guard preserving the mage.
Dorseas: Amazing. 2 Armor 11 health ageis 1 and regen 2 is TOUGH! And on top of that he has his insane passive healing ability to any other creature in the zone. Very good!
Knight of Westlock: Solid big gun. Versatile, can tank a few hits, and if all else fails, has a pretty good dodge.
Griffin: I like them, but they are not as good as some people think IMO. 1 Flyer hinders them and they suffer from bad initial dice. Would run maybe 1, no more in most books.
All clerics: Dawnbreakers initiate is really good for winning the positioning battle, and has solid stats. Clerics are ok, their 1 die heal and versatility are really nice, but works better with priest. Disciples can be good in temple builds or kill zones, not much other uses imo.
Brogan: Beast. Kills everything not flying. He's only very good in certain situations, but he is worth every sbp and point of mana imo.
Artimuis and Light of dawn: Good range attackers. Artimuis is best as a secondary threat after something like blue knight. Be prepared to dispel chant of rage asap. Light of dawn is cheapish and has solid stats. Run lesser teleports to move them around.
Aurora: Really good vs minor creature swarms. Pretty good stats and all. Depends on build whether you want to run her or not, but I would consider her for sure in a lot of pallies since he struggles with swarms.
Think that is most everyone important, tell me if I missed anyone
!
PS: Forgot to mention this. The lightning knight opening is puddnhead's idea. The "heaven temple"build uses Coshade's priest's opener, but I actually did a lot of testing: 5 other openers as well so I came up with that a bit on my own I suppose.