I don't know when this started happening...
I don't know which update allowed this to be, but I have been able to play every_single tactical battle I have entered so far! This used to not be the case. I am currently playing on a system which does not meet the min specs. So I am exceedingly happy that the tactical battles appear to be available for me. The battles occur in slooow motion, but at least I can play them now! Who woulda thought that a high profile game made in 2010 would be able to be played on an older system which uses an integrated graphics card! Thank you SD for making this happen!