Great point.
Lets take a step back... the reason why you have owners, organizations, territories, and teams is to enforce authorizations of who gets to do what with the data.
So the first thing to define is how you want groups of people to have access to data. It is best practice to use the C4C territory mgmt feature to define territories, assignment of people to territories, and rules to define how a territory is determined for master data.
In most scenarios you will at a minimum setup some basic region based territories and then align the Accounts to those territories. In directly the people who are part of the territory will get authorizations to read or write or no access at all to the Account data. From there, when transactions are created for the account, the territory is automatically copied over from the Account and you also have the same authorizations applied to the transactions.
Then of course you will have more granular authorizations for the transactions themselves which is where sales teams come in where you may want to grant access to other people who may not be part of the territory.
Now for lead mgmt, as you described complements above.
When you allow the creation of marketing leads, again it is best practice to create lead routing rules to determine the Sales Employee party of the Lead "Team". Imagine marketing creates leads. The lead routing rules then route the lead to the regional sales manager who can then assign the lead to one of his/her sales rep (make the sales rep the "owner" of the lead"). Or you could create more sophisticated rules where one rule = one sales rep = "owner" (employee responsible party) of the lead.
Now if you are the sales rep creating the lead, then you can make yourself the owner of the lead and then create a lead routing rule to ignore running the rules if an owner is set.
Next when the rep qualifies the lead, ultimately the rep needs to assign an account or create a new account. This is where territory mgmt kicks in.
If the lead does not have an owner, and the rep associates an account, then the lead owner gets set as the account owner.
If the lead does have an owner, and the rep associates an account, then the lead owner is maintained.
Then when you create a follow-up opportunity from the lead, then the lead owner is carried over to the opportunity owner.
Again if the lead does not have an owner, and the rep associates an account, then the lead owner gets set as the account owner. The follow-up opportunity from the lead would then carry the lead owner (which is the account owner) as the lead owner.