When the SAM is in the air it would face the same issue with agility because it is fat and if not why would a fat A2A missile should have issue with agility ? Unless You say what works for SAM should not work for AAM
SAMs are not designed with the same constraints as a BVRAAM. You can make the same large and heavy yet still make it high performance and able to impart lot of agility by focusing on other design features, staging and control surfaces. Design margins and trade spaces on an BVRAAM are much narrower as should be obvious.
That is what I stated for long range they would just loft the missile at 25 Km and dive on the target from top they dont need agility there but for fighter aircraft where you want to hit say a 9G manouvering target you need agility the range would decrease but it would still hit the target.
Not necessarily unless one assumes that the missile is kinematically limited and can still maneuver to the same level as lighter more optimized missiles when kinematics are not a factor.
Not exactly true you can have the most accurate weapon with HTK capability but a large warhead would end up maximum destruction of target compared to the same missile with smaller warhead. The Radius of Destruction of a larger warhead will be higher than a smaller one plus the destructive potential
The objective of a missile intercept is to first and foremost complete the intercept and then to obtain a favorable outcome i.e. fly-out and find and fix the target and then obtain your overall objectives. Warhead sizing is part of that trade space and optimizing warhead is purposely done so that you carry the right sized warhead for the purpose and not something that is too small or too big which will be sub-optimal and will lead to shortfalls elsewhere.
If an AMRAAM say with 23 kg warhed and RVV-BD with 60 kg warhead hits a fighter what is guranteed to cause more destruction to a fighter or a bomber ?
If RVV-BD++ carries a 200 kg warhead which will have more destruction on target? What about RVV-BD Super ++ with 500 kg warhead? Get the drift? Warhead's exist to achieve a desired effect on target and you model, develop and test to verify that you are right sizing it for the mission. Warhead sizing can be used to compensate elsewhere such as upping warhead size to overcome kinematics, agility or accuracy issues.
Even the more accurate SAM in the world carry larger warhead than a BVR missile why dont they carry warhead of a MANPADS even with HTK capability ?
As I mentioned there are nuances of design trade spaces at play here. How do you make a missile more accurate? First you start by providing it the most accurate tracking information to it (this has nothing to do with the missile itself and is a great way of improving the accuracy and performance of your missiles by addressing the kill chain). If you can improve the accuracy of your tracking information then that provides a major boost to the accuracy of your weapon. Improvements in networking and two-way data-linking are also known to ensure more accurate information along with PNT advances. Second you make the seeker more accurate by improving its capability. Modern SAMs with the highest seeker cost margins have moved to higher bands (such as Ka Band) which is great for discrimination and the narrow beam allows the seeker to see farther and as a result begin to use its seeker earlier in the intercept phase when it can communicate with the primary sensor via improved data-links. This gives the weapon a better chance to be at the right place at the right time to complete the intercept as all these things by themselves or combined eliminate errors that creep in during long range cruise profiles/intercepts - errors that the weapon has to correct for in the end game and hence carry "margin" when it comes to kinematics/motor and warhead.
Next is the agility portion i.e. can you incorporate technologies such as thrust vectoring, advances flight controls or other things (say dozens of pulsed rocket motors as some missiles use) to make the missile more agile? Warhead sizing, type and modeling is part of that trade space and is not an independent variable but something looked at during the systems analysis. Each of these elements comes to play when designers design a weapon against a particular threat type(s). You don't want to pay the cost of a weapon that carries a larger motor than required, more agility than required to carry out the intercept against a desired target set, and a larger or smaller warhead than what is required. Doing so results in penalty elsewhere (design weight, size, cost, complexity etc etc etc).
Well lets say Yefim Gorden disagrees with you , He clearly thinks that it effective for both just the range to target differs.
The link you have mentioned clearly states that it is not as agile when compared to other short and medium ranged weapons. Similarly they claim that they can intercept targets that can maneuver up to 8Gs. Is this the same level of agility and target performance the R-77 can handle? If so, is the R-77 incapable of successfully intercepting 9G+ aircraft? If not, why is there a difference b/w these two weapons?
Does the missile really have to pull 9G to take on a 9G target ?
Way More Gs under most intercept scenarios (unless you obtain speed parity in which case the aircraft can simply run away). Air to Air missiles aren't designed to be able to pull 40 or more Gs for fun's sake but because it is required. If you loft the missile higher and use a second pulse to accelerate it further while also gaining speed by trading altitude you will pull a huge gap between your velocity and that of your target. Fighter targets can offload fuel and weapons/pods etc and sustain b/w 7-9 Gs at a favorable altitude. There are fighters out there that can pull instantaneous Gs well beyond the 9G soft limit (Rafale can pull up to 10.5-11 Gs, Eurofigther around 10Gs, and F-35A has been tested to pull 9.9 Gs instantaneous). A missile will need to pull many times that amount if it has to turn with the aircraft and since it can't throttle unlike a fighter, even the instantaneous abilities matter.