I have served my Tenant with an unlawful detainer and complaint last Friday.

If still no, more than likely the next question will be to you asking if you wish for a judgement for Forcible Detainer. if you say yes the judge will inform the tenant they have ex amount of days to move out.If it seems confusing or overwhelming, go to eviction court ahead of your date and watch the proceedings for yourself.

It's called Unlawful Detainer. 

Excerpt from our rental criteria:RESIDENCE/RENTAL HISTORY1.We will examine the most recent five years of residence history and all legal history.2.Home ownership will be verified through the tax assessors office and/or credit report.3.Rental history will be verified through the property owner and/or rental agent. 4.Rental history reflecting any unpaid past due rent, damages or fees will result in denial.5.Rental history showing excessive property damage, excessive noise, or unruly behavior will result in denial.6.Three or more notices for failure to pay rent and/or to comply with the terms of the rental agreement, within a 12 month period, will result in denial.7.A person with an eviction or unlawful detainer on their record may be approved if full restitution has been made.

My seller had spent tens of thousands of dollars on dumpster fees because of squatter who clearly loved bikes and mattresses, forcible detainer to get said squatter off of the property, and code violations to city of Oakland for bikes and junk created by squatter. 

It's probably pretty vague.If so, you're highly unlikely to win in court.Also, it appears you may be incorrect about your eviction assumptions.You state you, "found 3 forcible detainers".

Unfortunately, in my case he was asking for way too much cash and honestly that would have not guaranteed he was moving out.I ended up hiring a legal firm to file an "Unlawful Detainer" lawsuit.

The new owner would have to evict using unlawful detainer, however I'm not sure how Corona Virus may have affected my ability to get them to leave legally, so I'm wondering if the deal is worth the hassle.

An additional late fee gets added every 5 days until the court date is set up for Unlawful Detainer.

(a) For any residential unlawful detainer action that includes a cause of action under paragraph (2) of Section 1161, any defendant may, at any time between the filing of the complaint and entry of judgment, notify the court of that defendant’s desire to stipulate to the entry of an order pursuant to this section.