“Good morning, good morning!” the General said
When we met him last week on our way to the line.
Now the soldiers he smiled at are most of 'em dead,
And we're cursing his staff for incompetent swine.
“He's a cheery old card,” grunted Harry to Jack
As they slogged up to Arras with rifle and pack.
But he did for them both by his plan of attack.
The nominal group most of 'em elaborates the the nominal group the soldiers he smiled at by clarifying it. The interdependency relation is paratactic, because either nominal group can serve as Carrier in its own right.
Again, the motivation is textual, not just in conforming to the rhythm of the poem, but because the elaborating nominal group in this position forms a single information unit, with most as the focus of New. But this has the added effect of making dead the focus of New in a following one-word information unit. In this way the poet makes his point by giving maximum textual prominence to both most and dead, together with the previous focus smiled at within the Theme.
// 1 ‸ Now the / soldiers he / smiled at are // 1 most of them // 1 dead //