Dr. Miriam Yoshida is the principal villain of “Scoop Chase,” the eighth and final episode of the original Bubblegum Crisis OVA series. He is a brilliant but deeply unstable engineer employed by Ebisu Corporation, one of GENOM’s wholly owned subsidiaries. His technical work has helped elevate Ebisu into the upper ranks of GENOM’s corporate network, but Yoshida believes his superiors take credit for his achievements and deny him the status his genius deserves. (AnimEigo)
Rather than simply seeking money or issuing political demands, Yoshida decides that defeating the Knight Sabers will prove his superiority and force GENOM to recognize him. He deliberately releases Boomers into MegaTokyo and secretly observes the Knight Sabers fighting them, gathering combat data on their hardsuits, weapons, movement patterns, and apparent performance limits. (Bubblegum Crisis Wiki)
After collecting enough information, he removes four Boomers from a GENOM production line, falsely labels them defective, and personally rebuilds them into specialized anti–Knight Saber combat units. He then sends them to attack A.D. Police Headquarters, partly to test the machines and partly to draw the Knight Sabers into a controlled battle. Yoshida observes the assault from a helicopter and openly tells Daley that he has no ransom demands—he simply wants the building destroyed and expects the A.D. Police to summon the Knight Sabers for him. (Bubblegum Crisis Wiki)
His plan initially works. One of the Boomers penetrates the headquarters computer system and turns the building into an automated death trap, manipulating doors, elevators, security systems, and other infrastructure while the remaining units engage the defenders. (Bubblegum Crisis Wiki)
Yoshida’s fatal mistake is that his combat analysis is already obsolete. The Knight Sabers arrive wearing newly upgraded hardsuits that exceed the limits recorded during his earlier tests. His customized Boomers are destroyed, and Yoshida attempts to escape by helicopter, only to be intercepted and arrested by Leon and the A.D. Police air units. (Bubblegum Crisis Wiki)
The series does not provide individual names or detailed model numbers for all four units. Collectively, they are best described as customized anti–Knight Saber Boomers.
Their defining characteristics are:
They began as ordinary GENOM production-line Boomers rather than entirely new creations.
Yoshida secretly removed and rebuilt four units.
Their combat programming was based on data collected from earlier Knight Saber battles.
They were specifically tuned to counter the Sabers’ known hardsuit capabilities.
At least one possessed advanced computer-intrusion capabilities and successfully took control of A.D. Police Headquarters.
The group operated as a coordinated assault force rather than as random rampant Boomers. (Bubblegum Crisis Wiki)
They appear to employ a power-boosting system associated with Yoshida’s work, increasing Boomer battery life and power output. That technology helps explain how his modified units could sustain an extended attack against both the A.D. Police and the Knight Sabers. (Raven's Garage)
For your campaign, the four units could be divided into distinct battlefield functions while remaining faithful to the episode:
Command/Hacker Boomer
The unit that breaches computer networks, seals doors, commandeers elevators, disables communications, and converts buildings into automated traps.
Assault Boomer
A heavily armoured close-combat unit designed to withstand direct attacks from Priss or Sylia and overpower hardsuit users at short range.
Interceptor Boomer
A faster unit engineered to predict evasive movement, pursue Linna, and prevent the Knight Sabers from repositioning.
Fire-Support Boomer
A ranged unit using heavy weapons or suppressive fire to isolate the Sabers and force them into positions selected by the hacker unit.
Those role divisions are a campaign interpretation; the confirmed lore establishes four remodeled Boomers, their anti–Knight Saber purpose, their coordinated attack, and their use of stolen combat data, but does not provide a canonical class designation for each one.
Yoshida is not simply a mad scientist building monsters for destruction. He represents technological arrogance without adaptability. His Boomers are carefully designed to defeat a fixed picture of the Knight Sabers, but he never considers that Sylia might improve the hardsuits. The moment the Sabers evolve beyond his collected data, his supposedly perfect countermeasures collapse.
His entire scheme is basically a very expensive lesson in why you should never balance a boss encounter using last patch’s statistics.