FWIW, U.S. fighter pilots execute a procedure called a "join up" on a daily basis (if not multiple times a day). In this procedure (with 2 fighters) #2 joins with #1 in an expeditious manner. If the join up is done too aggressively with too much of a crossing angle, a beginning pilot may want to bank hard, losing sight of #1 under his wing. Due to the danger of a collision, new pilots are taught to "suck it up" and overshoot lead, passing under rather than risk losing sight and colliding. Better to get chided in debrief than lose 2 aircraft.
This is hammered into their heads at an early age. To see a Russian pilot do the same stupidity executed maneuver losing sight of the target twice, the same way, tells me we may be spending too much on new fighters, at least with the Russian threat (or lack thereof).