different spoolup times due to the fcu/mec - beyond limits of the supervising electronic control. this is unlikely to occur if toga sw are pushed after ensuring even spool up manually till the N1 is at the recommended figure (50% as a ballpark figure)
i've experienced this on go around on B747-300 with CF6-80 (MEC/EEC)
and on A310 if Go levers are triggered EARLIER than recommended during take off (including FADEC PWs and MEC/PMC CF6) - the problem exists but not so pronounced during G/A due to 'flight idle'
no apparent probs on FADEC 744
aircraft/engine type info would help