All that should need to be said here is that SO MANY of Segas best games were developed out side of Sega Japan...
Shining Force, Gun Star Heroes, Wonderboy, Comix Zone, Sonic Rush, Bayonetta, Crush, Streets of Rage, Beyond Oasis, 2K series... The list is big.
There is no part of me that feels that Shining Force feels like Sonic Rush or NFL 2K2 feels like Bayonetta... They simply don't.
I could say Gun Star Heroes feels more like a 90's Konami game then a Sega game and I'd be right... But it is still a Sega classic. Likewise Sonic Rush feels FAR more like a Sega game to me than Sword of Vermilion ever will and that was developed by AM2 with Yu Suzuki involved...
The bottom line here is that there has never really been a uniform Sega style and not all of Segas most 'Sega' classics are even made by Sega...
Total War games are an absolute masterpiece, I've been hooked on them since the very first one and that was published by EA... Usually I'll avoid buying EA games or I did at the time.
They have fantastic game play, fantastic music, they are genre defining, revolutionary, unique in that nothing comes close to doing what these games do... They are, to me what every Sega game should strive to be.
Not to mention Sega have been funding their projects since 2005, have grown the team since then, added a console team and own the company.
There is NOTHING about them that isn't Sega right now.