I think the biggest obstacle I'm seeing against the "second team in a new country" idea is cheating, so let's bring up as many different ways that people could cheat as possible and let BB staff disprove that it's going to affect the already great game that BB is.
1. Ruining the drafting process by deliberately coming last, taking the good players and hindering their growth.
2. Switching players between several managers between teams.
3. Easier to make/manage farm teams (my country does it for your country and yours does it for mine).
(edit: there are likely more but this is all I could think of in a short time)
I have no expertise in these, but here are some thoughts I have in response to each:
1. Let's remember that second teams will almost all be in countries with limited activity, so these are not dominant nations on the world stage with almost complete certainty. Italy will not be planting owners in USA to do nothing but waste HOF talent by hoarding them, because there won't be any owners getting their second teams in USA. I think this is a red herring.
Further, if you pay for a second team in a small nation, you've got a decent chance to be pretty good. You'll still be competing against some bots, most likely, but overall making the competition better somewhere. I cannot fathom why anyone would spend this money just to be a foreigner who deliberately takes a team just to make it suck.
Also, tanking is not cheating, as I understand it. I've seen teams deliberately finish last almost every season. They relegate, then they rebuild and return. It's part of the game.
2. This is already something hard to police, since by definition it involves a lot of owners. But other than trying to ruin game shape for NT-level players of other countries, it's not really anything but childish behavior. If an NT player's being sold repeatedly, those nation's managers will notice and report problems. If people are doing this with other guys, then who exactly are they hurting? I could care less if people want to keep transferring players and wasting their money, as long as they aren't deliberately overpaying.
3. I think this is also a red herring for the same reasons as No. 1. These secondary teams will not be in big nations. And anyone who wants to take a team that's currently a bot and develop the talent there for whatever reason should be welcomed, I'd imagine. Those native players can only be useful to the NT/U21 managers of that country, right? What other concern is there here?