Differences Between BBTag and BBCF
BBTag adjusts most characters from BBCF drastically in order to fit their move sets into a tag game. Many moves are cut, and others are re-purposed. For example: 
Ragna the Bloodedge's 6D
GuardMidStartup21Recovery14+16LAdvantage-12 is repurposed to become his 2BGuardAllStartup21Recovery14+16LAdvantage-14, and his 2B
GuardLowStartup9Recovery15Advantage-3 has now become his 2AGuardLowStartup7Recovery12Advantage0. Accordingly, the frame data is adjusted in order to fall in line with their new purpose. 2A (originally 2B) is faster and has better advantage on block, and 2B (originally 6D) is slightly more minus on block.