Firstly, I don't like the idea of running 3-2-3 line of ANYTHING. I'd ratherstick to 3-1-3 and use 3-4 RCs.
Secondly... 4 Kyurems is better IMO. It's your main attacker, and it's good to start with. Zekrom requires Plus Power to one-shot it turn one, and Donphan will think twice about hitting it for fear of getting one-shotted by outrage. If you're tight on deckspace, I might justify taking out 1, but only then.
Thirdly, 2-2 of CDL is better. Running 1-1 leaves it vulnerable to one piece being prized. Though it may not be VITAL, it's an option you want to keep on the table, not leave up to chance.
Fourthly, Luna-sol/rock is 1-1 for sure. Serperior might not even see any play for fear of Reshiram spam and catcher to get an easy prze off Reuniclus. Therefore, it may not even be NECESSARY at all.
Fifthly, Vileplume is a shaky tech. Even if you decide to use Oddish for Catcher bait, what's the point? You just burning unecessary resources, and for what? So you can prevent yourself from RCing into Feraligatr? Lock your own Communication to prevent you from getting a LEGEND piece? Lock your Revives which can be used to get Kyurems back? Prevent yourself from using Energy Retrieval to get water energy after losing a Kyurem? IMO, it hurts more than helps. I vote no Vileplume.
Sixthly...
3-1-3 Feraligatr Prime
4 Kyurem
2-2 CDL
1-1 Lunasol/Lunarock
Total: 17 pokemon
17 is actually not bad. If you feel comfortable with starting with Mantine at the start to search out your Feraligatr early, by all means add in 3. 20 is STILL an acceptable number. You could even add in a Cleffa or two and still be fine at 22. More Communication bait, and between Junk Arms and Communications, you shouldn't have to worry about getting unwanted pokes for Lostgar/Mewgar to lost zone away, anyways. In reality, the pokemon line isn't really much different from Reshiboar in terms of similiarities. Feraligatr=Emboar. Kyurem=Reshiram. CDL=Ninetales. That's the skeletal lineup for ya. No, Ninetales isn't the same as CDL or vise-versa, but what else are you going to use? Similiar lines... Different stratagy...
Sorry for the wall of text. ^^;