Need Help with a Fighter/Barbarian multiclass
I'm joining a campaign which the DM has said will be quite challenging, so I think it's a good idea to try and optimise the character as much as I can. The campaign starts at level 1 and is aiming to end at level 20.
The general concept is a Human who uses a Glaive, eventually getting the polearm master and sentinel feats, but I'm just unsure of how to multiclass optimally or whether just to stick to one, because I think the flavour of Barbarian suits him much more, but the Fighter offers more versatility, and I'm unsure of if a multiclass will be better than the sum of it's parts or worse.
I'm thinking 1-6 in Battle Master Fighter, then 7-20 in Berserker Barbarian. My goal (mechanically at least) is to be a high damage frontline crowd controller with good defences, and I'm also looking to play something with zero magic since I normally play spellcasters and wanted to try a full martial character.
Are there any ideas I should take into consideration - does this multiclass setup seem good? Should I stick to just one of the classes?