Well, that does not reflect my feeling :
The shafrir 2 is a limited missile of its generation, but it is not that bad, and not as bad as the AIM-9B or AA-2.
I made a full 1973 campaigns and my kill rate with around 50% with this missile.
The Shafrir 1 is mainly here for pure esthetical purpose.
The Israeli tactic, which I used to great effect with Mirage IIIC and Nesher consists in fly at high speed, than turn hard, leeting your speed drop very low but gain a high instantaneous turn, while avoiding overshooting and gain an advantageous position, and fire.
This technics kills a Mig21 (F, PFM, or MF) in 3-5 minutes and is also efficient against all potential ennemies (Hunter, Mig17 and 19) and even Mig-23s (I made a Nato 1980 campiagn with a Mirage IIIC)
Of course, against a F16 or the like, you're dead
I think that you try to fight in terms of constant energy management, which is not the right way to do in Mirage.
The point is to think of your energy as a "bullet" : you keep it until you have an opprtunity, you "fire it" (ie hard maneuvers without energy considerations to get into firing position), then you "reload" by extending.
The point is that you must feel the moment when you must switch between tight turning to get a firing solution (offensive) and tight turning to increase delexion and be safe (defensive), remember that your ennemies weapons are also very limited so as long as you have a reasonnable deflection angle, you can quickly go beyond your ennemies weapons enveloppe.