ditto.
as for shieldwalls and twohanded swords I got a lot to say. But since I am the gym I will be short (well I allready am, but I will be short with my words).
Interlocking shields is pretty good for the push but when you are spearline against spearline you generally want to be a tad bit looser. You want to be able to bring your shield up and down quickly, after all.
This is specially true for swordsmen and in a line battle their role will most likely be as part of a group meant to smash through the enemy line and cause disarray.
as for the "greatsword" one wonders what the rules mean by that? Is it closer to a 15th century longsword or a 16th century zweihander (which is used more like a sharp staff or short spear with a healthy helping of cleave)?
the latter is often mentioned as an anti pike weapon, but aside from woodcuts showing them used against pikemen we dont have, to my knowledge, any sources on this claim. I seem to recall that we do have sources mentioning that they were used by protectors of the company banner and by budyguards. Naturally, you can controll a large zone with the weapon and it is scary to boot.
The 15th century longsword is a highly agile and versitile weapon which becomes popular among knights once their armour has reached a level of quality that makes their shields a bit obsulete. A warrior decked out in full gloranthan bronze plate would qualify, I would say, and since Glorantha bronze is similar but not the same as ours I am sure you could make both a longswprd and a zweihander out of it.
source: dude, trust me