SUMMARY
In a clash between DC and Marvel characters, the Flash effortlessly overcame Hawkeye, leveraging his seasoned experience against Captain Boomerang and his camaraderie with Green Arrow, which endowed him with a profound understanding of archers' strategies. The JLA/Avengers crossover event depicted an unexplained amalgamation of the Marvel and DC Universes, culminating in a confrontation between these two legendary superhero ensembles. Flash's velocity and adeptness with analogous weaponry granted him the upper hand against Hawkeye and his trick arrows during their urban confrontation.

Literature Review
Within the JLA/Avengers crossover narrative, the DC's Flash identified a member of Marvel's Avengers who bears a striking resemblance to one of his archetypal adversaries.
During a Marvel/DC crossover event, the Justice League's Flash highlighted the Avengers' Hawkeye for possessing an almost identical skill set to the renowned antagonist Captain Boomerang. This resemblance enabled Flash to dodge every one of Hawkeye's trick arrows and effortlessly subdue him, owing to his past encounters with Captain Boomerang.
JLA/Avengers #2 – penned by Kurt Busiek, illustrated by George Perez, colored by Tom Smith, and lettered by Comicraft – presented the inexplicable merging of the Marvel and DC Universes, leading to some characters appearing in one universe while others emerged in the alternate. This scenario eventually led to a colossal battle between the two teams.
As Superman and Thor engaged in aerial combat, and Captain America and Batman sparred across city rooftops, Flash and Hawkeye dueled at street level. Despite Hawkeye's impressive array of trick-arrows, they were no match for Flash's speed and his familiarity with similar weaponry, used by both foes and allies.
Flash's Experience With Captain Boomerang Allowed Him To Evade Hawkeye's Trick Arrows Easily
Flash frequently confronts a group of villains known as the Rogues, with Captain Boomerang being a prominent member. Captain Boomerang has utilized a plethora of trick boomerangs over the years, ranging from explosive to standard bladed varieties. Despite his relentless attempts to gain an advantage over the Scarlet Speedsters, his efforts have yet to yield success. Flash's prolonged battles with Captain Boomerang have honed his alertness to projectiles, enabling him to adeptly manage Hawkeye's attacks.
Hawkeye, a mainstay of the Avengers roster, is widely regarded as one of the finest archers within the Marvel Universe. His precision is so remarkable that Hawkeye once accomplished the extraordinary feat of killing a target with a flicked fingernail. Over time, he has further honed his skills with an arsenal of trick-arrows that emulate a diverse range of effects. Nonetheless, Flash was still able to outmaneuver Hawkeye.
Flash Has Experience With Archers, Friend And Foe
Flash's experience extends beyond battling Captain Boomerang; he has also collaborated with Green Arrow for many years, whose modus operandi closely mirrors Hawkeye's. Green Arrow's fame stems from his utilization of extraordinarily inventive trick arrows. Flash is undoubtedly familiar with these, having witnessed Green Arrow employ them against Justice League adversaries, particularly given that malevolent speedsters are more prevalent in the DC Universe than in the Marvel Universe.
As an Avenger, Hawkeye has safeguarded the world on countless occasions, yet he has seldom faced speedsters akin to Flash, who is generally acknowledged as faster than Marvel's speedsters. Conversely, Flash has regularly contended with characters similar to Hawkeye, who rely on long-range tactics and gadgets. This experience proved decisive when these two iconic heroes clashed, resulting in Flash's triumph over Hawkeye due to his seasoned interactions with a quintessential Flash adversary.