A national vote was not called because 3 previous ballots in 1982/3 had all voted against a strike. One month into the 1984 strike in Sheffield at the delegate conference AS had the opportunity to amend the rules to a 50% + 1 majority decision from the existing 2/3rds for a strike. He didn't because as you say the NCB led by McGregor had developed a productivity bonus system that was particularly beneficial to Nottingham and Welsh areas and he feared a repeat of the previous ballots where there were 55-61% results against a strike. The strike by that time had also gone on longer than previous ones as the Tories had pressed the NCB to build up coal stocks in anticipation of industrial action and there was no prospect of Thatcher capitulating like Heath did. AS thought other industry unions would come out in support and paralyse the country but he was disliked by the more moderate union leaders for his communist sympathies. With no national vote taking place they had a reason not to endorse it as official industrial action
Tactically AS got it wrong he should have gone in Winter rather than the start of Spring but events took over out of his control with the unofficial strike at Cortonwood leading to a domino affect. Sadly it all ended in recriminations between the NUM and AS over financial irregularities years later.
An intelligent man who was blinded by ideology but he was right about the list of closures I know because I had access to it in later years, thats another story.
My Moms side were all miners. My Dads were from Nottingham, nothing to do with the mining industry, they don't have fond memories of Yorkshire folk abusing them and calling them scabs as they were driving their cars to work. They're Pies not Florist so will be delighted if they fail to go up.
A fascinating part of industrial history that impacted on some of the work I was doing in the 80s/90s.
As for drawing a line under it there is still bitterness in the old mining communities as shown by one visit I made some years ago to a distant elderly relative in Rossington. She saw a neighbour across the road and said we don't talk to them because they're scabs who worked during the strike. I said what the 72/74 strikes? She said no the 1925 one!