Of course this is all hyperbole and hypotheticals but this is my concern. If I have a friend who with another friend are seeking to buy a small business that is going to cost them a price that's equal to half of both their assets, regardless if a loan is taking a considerable slice of that I would tell them thats its likely a mistake. Of course that could be calmed to what degree a 3rd party is involved, but that completely changes the calculus as for it to make sense I'd argue that person or group should likely be bringing the largest amount of cash in the purchase for it to make financial sense. Thus the scrutiny falls on that individual more so than the credibility of Bell Downing.
All caveats aside if we go with Bell Downing we are talking about having the least cash rich owners in the first division. Of course that could be fine, maybe they demonstrate themselves to be able to run one of the most cost efficient clubs, but it's a worthy concern regardless if they can secure outward money.
I dont disagree with the clubs you mention as exemplary, but the resources at their disposal do completely change their decision making regardless if their largely self sustaining. The Kroenkes are collectively on the cusp of being in the 100 richest people in the world. West Ham have multiple partners with their two main shareholders worth collectively more than 10 billion. Spurs are more akin but also Levy runs maybe the most efficient financial balance operation regardless of his faults in the EPL. And even so they would have 6 times the amount we do between him and Joe Lewis.
These are all just possible concerns, but in the inverse what are we gaining from B/D besides local knowledge. Neither have owned football assets, neither I would say are likely to dramatically come into more wealth. Of course they can praise a level of business acumen, but all of these people can to a degree. When judged to a point of comparison I dont know why I would defend their interest if they are mainly the sole party as first choice removed of being Scousers.