Just for the record the A-10 and the 262 are not, repeat, are not comparable in speed. The 262 was quite a bit faster than the A10 is today. And no, when they fire their gun (which during actual combat is a three second burst) they do not lose 200 mph. Maybe 10 kts tops. And the A10 doesn't slow down to attack tanks, that makes it only more vulnerable and less manuverable. Coupled with its high G manuevers its engines are at mil power. So to think that the 262 would slow down to do ground attack is 'non sequiter'. It does not follow. Plus doing that in a 262 would make it less stable a gun platform, and more vulnerable to ground fire which the 262 was very, and on top of that its poor acceleration would have made it easy easy pickings for enemy fighters.
Turbojets without afterburners do not acclerate as quickly at propeller driven aircraft, what jets excel at is the continuation of their acceleration past the point where propeller aircraft have their prop tips going transonic/ supersonic.