Bad idea.
It is not intuitive, limits the possibility of arranging tactical battles, and in the result will make Strategus battles less interesting for casual players - they will not get accepted in the roster of their favorite team due to the limited number of slots. In fact it makes it less interesting to all players, as pre-arranged battle requires preparation, finding time, and players count on spending some some fighting in such battle. In your model the battle would look just as one of the regular cRPG rounds. Is it worth it to leave cRPG server to join Strat server for just one round? For me - probably yes, because I'm in the faction, but for random player with x5 on cRPG server - probably not.
Plus - and that is even more important - in your example team A will almost always win - they need average 1:3 K/D to win, while team D needs average 3:1 K/D. Number if players in each team VERY important. Just imagine yourself fighting against three opponents at the same time... well, it may be difficult, right? Defenders are simply heavily outnumbered. I have seen battles where team with lower number of tickets won thanks to better skill, tactics, organization and sensible player base.
Currents/previous scaling system worked pretty well, it may need some tweaks as to the level on which the scaling is adopted.
