One per client in a single drop. Every field tile has a small ×N in its corner. Drag the tile for one field; drag the ×N for one per client — initials side by side, signature blocks stacked. It works on any type, so two names, two emails and two phones are one drag each.
 
The count only includes clients — buyers, sellers, tenants, landlords. Agents, brokers and the AutoFill system signer are excluded, because they sign once in one place. If a document has fewer than two clients the badge doesn't appear.
Editing several at once. Select more than one field and the Properties panel switches to bulk mode: reassign the role (showing "Mixed" when they differ), toggle Required, group them, or delete them together.
Shortcuts: ⌘C / ⌘V copy and paste the whole selection with its layout intact, ⌘D duplicates, ⌘Z and ⇧⌘Z undo and redo, ⌘S saves, Tab walks the fields in reading order, and right-click gives you the same actions plus "Paste here".
Resizing a selection resizes every field in it by the same amount, so a set that started uniform stays uniform.
Shape the set before you drop it. While a ×N set is on the cursor, R flips it between side by side and stacked, and + and − open and close the gap. The default follows the printed convention — initials read across a line, signatures stack — but plenty of forms want the other one, and changing it in mid-air beats dropping the pair and dragging the halves apart.
You don't have to hold the mouse down. Click a tile once and let go: the field rides the cursor, and each click on the page places one. Click the same tile again, or press Escape, to put it down. Dragging still works exactly as before — this is a second way in, and it is much easier when the spot you want is a long way from the palette.