Designs
A Nikah and a Walima are two occasions, and they are frequently two guest lists — the Nikah more intimate, the Walima broader. Sending one card for both makes that awkward to express; sending two doubles the cost and the confusion. These designs let both sit on one link while each keeps its own guest list, so a guest invited to the Walima alone sees the Walima, and nobody has to be told which parts of the card apply to them.
Each event carries its own timing, venue and guest list, and guests reply to each one on its own. The result is an accurate headcount per event rather than a single number you then have to interpret.
Invitations commonly open with the Bismillah and may name both families in a set order. All of that is free text, so the phrasing and the script are yours — the design does not impose a formula.
The link previews as a proper card in a WhatsApp chat, so forwarding it through family groups looks intentional rather than like a pasted URL.