They'll be the first to be shot down and the can be shot down from 300km away with meteor type sfdr missiles. Same goes for tankers. F18 won't be that's why carrier will have to come near.
Lot of pointless speculation... For instance, when some aircraft is trying to shoot down an AWACS/Tanker from 300 km, the target needs to be illuminated by the attacking aircraft till it’s in the range of active seeker of the missile. For Meteor, that’s around 30km. That means 270 km of your 300 km needs to be guided by FCR of attacking aircraft.
Now, tankers and AWACS don’t fly solo, they are heavily protected by an air combat group (usually in front of them). So what do you think that package would be doing? Waiting for you to finish off their most prized asset? No!
While you are guiding your large AAM to their AWACS or a tanker, your RWR and MAWS (if you have one- IAF does not) will start beeping like crazy and you will be either forced to break the “lock” to take evasive action or be shot down. Your AAM will never reach the AWACS.
Usually, as soon as the air combat begins, you need to take care of enemies that fire back first. If you succeed, only then you can work on other ideas.
Little off topic but in WWII, Luftwaffe faced similar dilemma. Bombing raids over Germany were carried out by both the 8th Air Force and RAF with bombers escorted by fighters. The short range of Allied fighters was an issue till 1944. They could not accompany the bombers all the way up to their targets deep inside Germany forcing Allied bombers to defend themselves against Germans.
Luftwaffe could either intercept the Allies as soon as they entered mainland Europe or could wait till the fighter escorts were gone. Wisely, they chose the latter and casualty rate among Allied bombing crew became unsustainable- forcing suspension of these deep raids.
Then something miraculous happened. In 1944, Rolls Royce Merlin engine was fitted on otherwise ordinary P-51 Mustang, turning it into the greatest American fighter of the war. It had the firepower and range to escort the bombers all the way up to their targets in Germany with enough fuel for dogfights.
Now, Luftwaffe had to decide: 1. Only attack the bombers of the strike package and prevent them from bombing vital installations while ignoring the Mustangs. OR 2. Fight their way through the fighter escort and attack the bombers only if Mustangs are destroyed.
The first option was a disaster. Mustangs easily picked out German fighters trying to attack Allied bombers and shot them down before any of them could deliver damage.
The second option became the only viable solution turning these bombing raids into a war of attrition.
The lesson here is quite relevant to your assertion.