Having reviewed the linked discussions, I will add that I agree with other statements that there is room for interpretation. What's more, I would argue that this is an area where a balance must be struck between the need to secure the deposit and the burden placed on those delivering it to the bank. In most organizations, these decisions usually come down to how much risk the organization is willing to tolerate.
In my unit, we travel from the church to the bank, and then all of those involved go in separate directions--none of which is back toward the church. Our risk analysis is as follows
[*] Donations batches are always logged in MLS and transmitted when the deposit bag is sealed--any discrepancy between what makes it to the bank and what is reported to Salt Lake will be found within a day.
[*] Donation bags have a removable strip across the top that corresponds to the unique identifier on the bag itself. This strip is stored with the donation batch.
[*] The donations batch consists of mostly checks. (In the previous four years, I can count on one hand the number of times I've seen more than $20 in a batch, and on two hands the number of times I've seen any cash at all) Anyone who wants to open the bag, steal the checks, and commit some kind of check fraud is inviting a visit from the FBI.
[*] When traveling in separate vehicles, the deposit is not placed in the drop box until the second person has arrived and can see the bag be placed in the box.
[*] The members we have handling deposits are, so far as we know, financially secure enough that $20 every six months or more is not worth the risk of being caught stealing.
Given all of those factors, the risk of something happening to the deposit is so low, it doesn't warrant the additional inconvenience of requiring we both ride in the same vehicle (in our local opinion). If we dealt with more cash than we do, I would certainly reevaluate that decision. Likewise, I would reevaluate that decision if we had people in poor financial positions working on the deposits. Both of those are conditions in which the risk of malfeasance increases.
I won't claim that everyone will be happy with this approach (let the flame wars begin), and I certainly won't claim that the risk tolerance will be uniform from one unit to the next. But I will recognize that when operating procedures reach a certain threshold of inconvenience, humans have a tendency to either ignore them or find creative ways around them, often to negative consequences.
Lastly, when I worked at a restaurant, I would routinely prepare deposits of values between $1500 and $3000 in cash. Sometimes two to three times a day. During normal business hours, the companion would ride in my car with me. At the end of the night, operating procedure dictated that the companion could travel in a separate vehicle. I imagine different corporations have different policies on the matter.