'If you listen to the Fighter Pilot podcast on EA, episode 83, then you get an idea of some of the limitations of the Growler operating with the SH will have. If you doubt the effectiveness of the F-35 against radars have a read of the following,
http://www.scienpress.com/Upload/JCM/Vol 4_1_9.pdf which shows that even with a worst case modelling the F-35 stealth features significantly reduce detection by early warning radars as well as those higher band targeting radars.
As SmithBS indicated both F-35 and SH/Growler would benefit from adversary airfields and VHF radars being targeted by cruise missiles etc. F-35 EA as stated by DigitalSea is going to be very effective given its low RCS and therefore low jamming power required to deceive threats.
Any IADS penetration is all about limiting how far along the kill chain, F2T2EA (which is Find, Fix, Track, Target, Engage, Assess) you get. The F-35 would likely spend a lot more time in the Find and Fix phases while a SH/Growler is going to be detected earlier and therefore spend a lot more time trying to defeat the Track/Target phase of the cycle via EA. The last thing either platform wants is to enter Engage Assess and have to defeat a weapon that is launched against it as in that case you have become defensive and lost the initiative. In the case of the SH it will probably drop its A2G weapons/fuel tanks to defeat the threat, meaning a mission kill for the adversary. Not sure what the tactics for an F-35 would be but I expect with internal weapons they would likely retain them when trying to defeat a threat.'
Growlers once they jam they become a sort of beacon which will notify the enemy "they are here" this is why F-35's will not have Growlers when penetrating advanced IADS. F-35's more than likely will get detected, not tracked, when they are in weapons range and that is when F-35's will turn on their EW and it is game over for the targeted IADS especially when carrying JSOW.