A brain.Which is better for SEAD/DEAD/deep strike in highly contested airspace?
First you have to know how the airspace is contested. Enemy fighters? Long-range IADS ? Short-range manpads? All of those at once?
The main error that you should never make is assume you have a silver bullet that can work perfectly in all conditions so that you can just turn your brain off and stop respecting the enemy's ability to improvise and adapt.
The loss of an F-117 in Serbia will remain forever the best illustration of why you shouldn't do that. State of the art stealth aircraft vs. obsolete air defense system, so the Americans turned their brains off, got sloppy, and the Serbian air defense scored a win against all odds, just by being more clever than their lazy opponent which had stopped considering war as something dangerous.
So the way to do deep strike in a highly contested environment is to start by not assuming a forum post can contain a one-size-fits-all answer. The truth is you need to have as good as possible a picture of where the enemy is, what the enemy can do, and then figure out a way to bypass most of the enemy defense, surprise those that you cannot bypass, and strike, with what you have, regardless of what it is.
It's a lot more complex than just player card battle and thinking all you need is to have aces in your stack. It's a real fight, against a peer adversary what will make a difference will be your skills at strategy, tactics, and deception.