Probably the safest thing would be to base your headcount on that provided by the "history" section of the series'
15th anniversary website. It shows a total of 10 games -- the 8 installments on the NEO-GEO hardware, plus Wild Ambition on the Hyper NEO-GEO 64 and Dominated Mind on PS1. So, you could call Mark of the Wolves:
- the last of the 10 games in the series
- the last of the 9 arcade releases in the series
- the last of the 8 releases on the original NEO-GEO hardware
In terms of gameplay, Dominated Mind feels like a modified version of its predecessor, RBFFS -- not unlike the SFII'/SFII'Turbo/SSFII/SSFIIX tweaks to the original SFII. Unlike the later entries in the SFII series, in my opinion, SNK regards Dominated Mind as a separate installment in the FF series as it adds its own new portion of story content to the series' overall plotline.
--Chris