Let me quote some of it, emphasizing some points in bold:
At the time of its creation, the Ukrainian military was considered the fourth most powerful conventional military force in the world, behind only the United States, Russia, and China. However, these forces were allowed to atrophy throughout the post-Soviet period[.] ... As a result,  by 2010 only 6,000 ground forces troops were being maintained in a state of constant combat readiness, while all other units would require at least a partial mobilization before being ready for battle. The air force was in a similar state of disarray, ... only 15 percent of all aircraft and helicopters were considered combat ready, and even these often lacked adequately trained crews. With a few exceptions, Navy ships rarely left port. Only four were considered combat ready. Air defense systems were unprepared, in part because of a ban on live exercises that was instituted in the aftermath of the accidental downing of a civilian aircraft during a 2001 exercise.
Furthermore, the lack of military reform meant that  Ukrainian forces were still based on the western side of the country, where they had been positioned in the Cold War period to defend against the NATO threat. ...
Lavrov emphasizes that Russian troops were stretched very thin during the first week of the invasion. In his analysis, Russian troops were not strong enough to prevail in an armed conflict against Ukrainian forces stationed in Crimea for the first week after the conflict began.  They remained vulnerable to a Ukrainian counterattack until March 13 when Russian motor rifle forces, equipped with heavy weapons, entered Crimea and reinforced the troops guarding the isthmus connecting Crimea to the mainland. ...
The final chapter, by Vyacheslav Tseluyko, discusses how Ukraine can rebuild its armed forces to deal with the threat of a future full-scale Russian invasion. Given Ukraine’s limited resources, he suggests that it should prioritize  combat training and repairing and upgrading existing weaponry, rather than purchasing new hardware. It also needs to greatly reduce noncombatant positions, reinstitute the draft, and  reform the Navy to focus on a coastal defense mission. In terms of strategy, Tseluyko calls for a  defensive posture that focuses on protecting large population centers. This would entail preparing for urban warfare and stationing long-range defensive MLR and SAM missile systems in urban areas, combined with  creating guerrilla formations that could attack enemy rear areas in the event of an invasion. Tseluyko demonstrates that using these tactics can  increase the costs of a Russian invasion to unacceptable levels.
Let me go through those points.
One, it wasn't just that only 6,000 troops were combat ready. In the aftermath of the fall of the pro-Russian government, lines of authority were to confused and loyalties too uncertain to know if even the combat ready troops would fight for the new proto-government.
Two, even before the war, I noted that Ukraine's army was deployed poorly from Cold War circumstances.
Three, if that authority and loyalty problem in point one was settled, even 6,000 troops quickly used to counter-attack into Crimea would have worked to defeat the Russians or at least deny them a quick and easy victory.
Indeed, pre-war, when a looked at a Ukrainian reaction to a Russian invasion, I speculated that a rapid counter-attack into Crimea was the way to go while the invasion force was light.
Although I readily admitted that it was a paper exercise and that the state of Ukraine's armed forces likely wouldn't support such an offensive.
In retrospect, if the 6,000 ready troops were loyal, they should have been thrown into a counter-attack quickly. German experience against Soviet forces in World War II showed that it was best to counter-attack fast with whatever was available rather than mass forces but let the Russians dig in.
Four, in discussing whether we should arm the Ukrainians, I've said repeatedly that it is pointless to send big ticket items and that Ukraine has enough stuff that, if upgraded and used by trained troops, is enough to fight the Russians. New major weapons are a long-term issue not relevant to the next 5 months or 5 years. Anything we supply should fill gaps or support existing equipment.
I touched on rebuilding here and here, for example.
Five, while I didn't mention the navy much, I've written that a focus on the ability to launch missiles at Sevastopol naval base and lay mines is important to build. Those capabilities certainly support coastal defense, too.
Six, I emphasized defending urban areas, too, where light infantry could better absorb a Russian mechanized offensive.
Although I also wanted small regular units used in a mobile role to inflict casualties on the Russian spearheads forward of the main defensive line along the Dnieper River, with the idea of preserving the army to deny the Russians a quick, decisive victory.
In that post I also mentioned point seven by saying Ukraine could use irregulars to harass the Russian rear areas and point eight about the need to make Russia bleed in any invasion.
Many times I noted that Ukraine wanted to deny Russia "style points" by making Russian power look unstoppable. An ugly Russian victory with heavy Russian casualties would dent Russia's image of power even if Ukraine can't halt the much bigger and better Russian army.
So not too shabby from my figurative basement in my figurative pajamas.