These were 1st Battalion of The Black Watch, This was my 'local' regiment and Armies in Plastic obligingly make a set of figures in kilts and Glengarries. The 'Pals' units were:
12 Battalion, York & Lancaster Regiment (Sheffield City Battalion). I named these figures after members of Sheffield Wargames Society.
1 & 2 Battalions, the (fictional) South Midland Regiment. Better know as The Knuston Pals, the figures of these battalions were names after attendees at this year's Conference of Wargamers.
The Black Watch advance in a professional manner.
The resulting immense crater was scattered with corpses.