Assemble first then when any glue has gone off thoroughly over night prime & then paint. Very few glues work well on painted surfaces & this should be avoided where possible. You can use super glue but it is better if you also use a little modelling putty or two part epoxy on heavy parts.
I am a little confused, I have both the infantry command packs & thought they had pole arms of one sort or another as the only separate bits.
Got you,that's why I missed it as I have not done any grenadiers yet as I was holding out for a firing line in bearskins & storming party in short mitre