Before I begin: I've never played against a pegasus spam, but I still feel that my opinion should hold some value. People should feel free to correct me of course if I'm off with some things.
The dark pegasus heroes are a good value for their points. For 50pts they gain fly, +1 armour save and +1W. It works because for whatever unknown reason GW decided that 6pts to gain scaly skin, on every single combat character was fitting. WoC pays 20pts and it's only for 1 model so yeah...
This means that they can have a lance, shield and heavy armour on a pegasus all for 150pts. Not bad.
However you should also recognize their weaknesses. S4 after charge and only 3 attacks. That's not super exciting. It basically means that they'll have to kill whatever they touch otherwise they're fvcked or stuck.
I think it's very important to remember because even with a lance they'll still only ever wound us on a 3+ and won't modifiy our armour by more than 3. Comparably we have more attacks, will have 64% chance to generate a 5th attack (which we should eventually do in prolonged combats) and hits home at S7. Not only does this mean that we'll wound on 2+, but we'll modify their armoru save by 4.
The last bit is important because against us their S6 will mean that a dawnstone will act as a 4+ ward in close combat. For them it'll mean that they get to reroll their 5+ armour save.
Now consider this for 1 second: A dreadlord with dawnstone will be just as easily to take down for our
scar vets as if it was just a hero (master I believe). His superior initiative, WS and wound doesn't have an effect compared to the hero characters. We can't compete in those aspects to begin with and both the hero and the lord have an equal amount of wounds.
What you should be worried about, I suppose, is a dread lord with the +2S sword instead of a lance and this is the biggest difference between the lord and the heroes (he can afford something else than defensive equipment). Oh and the extra attack lol ...
Not accounting for the rerolling 1s in the To Wound phase a dread lord will do 0,58 wounds against a scar vet with a 1+/4+ save.
Our scar vet against the dawnstone lord will do 0,84 wounds. Bam.
Now do remember that in every round following actually getting charged by a dread lord he'll be hitting you with his S4. S4 will do 0,093 wounds to the SV. Even less against a dawstone scar vet.
Now personally I think the I10 sword is a trap. You give up +2S every round of combat just to remove their reroll to hit. But what's the point really? S5 vs 1+ armour save won't be enough so you can't compete against his heroes in that regard and regardless you'll just have to survive first round of combat and then you can laugh at his rerolling to hit S4 attacks. There's no need to remove that and not get +2S. IMO at least.
If you were to have those 3 combat characters I would've done the following:
- 1+ armour save on all.
- GW on all (unless etheral units).
- Extra defence on all (+4 ward/dawnstone).
Our lord can afford some extra equipment so if you feel like it you can also give him the glittering scales light armour. OTS isn't a bad choice, just aim the lord at a character (ward).
My personal favorite is the dawnstone + armour of destiny lord with GW. Yeah just force that fvcker down the throat of your opoonent because they cannot possibly hope to take him down in CC.
Now uhm.. I don't know about you, but I feel much more confident in using my own list if I'm not too sure on the list borrowed. The list you have is.. ugh dunno what to say. Some of it seems random and I think it's very important for you to know what each unit should do and against what.
My take on a list? Core full of skinks. Special with templeguards (with armour piercing banner) and terradons, no CORs. Salamanders are fine. Dunno if cameleons can still fit into the list. Remove skink chief as needed.
You have to remembet that a 1 big unit of crossbow elfs isn't good against what I just presented. He can remove a few skinks models on long range or try his luck against our templeguards. None of which will be terribly bothered by it TBH. This obviously changes once we reach close range.
My strategy would be to remove the Dark Riders with skinks/terradons (terradons can also take out bolt throwers - only 2 crew members). Aim the salamanders at his Xbow unit. Aim a SV at same unit (will singelhandedly take care of it).
Keep your lord and the BSB SV around the templeguard bunker.
Think of it this way: At 2500pts you can have 9 units of skink skirmishers. He can't remove all of that just like that. Screen your bunker and push forward. He'll probably try and get around you with his fast units, but your main goal is to remove the following:
All core units, all bolt throwers, the harpies. Should you be lucky enough to catch a unit of Warlocks you can probably remove the unit by running it down. If you remove his bolt throwers you he can't hurt your mounted characters on range which means that if he wants to get points from you it's by killing skinks. Now should you get into CC with one of his characters and your skinks just pray that he won't remove more than 5 models. If he doesn't you can stick by being stubborn.
With a good bunch of skinks he can't quite as easily run around you. We have a 12" march + 12" range and relies on poison anyway so you should be able to do a number on his units.
Concerning the slann I'm more a fan of wandering deliberation. Some people will swear by high magic and that's fine. With WD you have 4 damage spells and 4 hex/augment spells. Obviously you can get those with high magic, but it's easier with WD. So yeah, I like it more, but that's just me
All of this is obviously just my opinion so take it only as suggestions and not how to beat the DE player the next time around.
He did have a fairly strong list (although it could be worse) than yours, so keep that in mind.