Incorrect Allegro Footprints

Thanks for the feedback. With the c0402x5r1a102k020bc, there is an issue in how we're linking the footprints, as it's showing multiple. We'll look into this and let you know when it's fixed. Thanks for reporting it.

As for Allegro import, it is not a typical Allegro footprint that is provided, but rather a batch file and/or padstack files. Here are the instructions for import.

(Automatically import)

The ZIP file downloaded from SnapEDA contains a BAT file which automates importing all padstack and the package. Follow these steps to import automatically:

Follow steps Extract files to your padstack path above.
In Windows Explorer, double-click allegro.bat.
Note: Some version of Allegro will repeatedly ask to import the padstack. If this happens, click the X button to close the Command Window.

If for some reason the automatic approach doesn't work, the manual process is here:

(Manual import)

Follow these steps to import into Cadence Allegro:

Extract files to your padstack path

Open the ZIP file and extract the contents.
In Allegro, select Setup > User Preferences...
In the Categories box, select Paths > Library.
In the Category : Library box, click ... after padpath.
The padpath Items window shows where you should place copy the downloaded ZIP contents. SnapEDA recommends you create a new path to store padstacks from SnapEDA, one path per download.
If you made any changes, restart Allegro
Import padstacks

In Allegro, select Tools > Padstack > Modify Library Padstack...
Repeat the following for each of the PSR files you downloaded:
In the Select Library Padstack window, select any existing padstack, then click Ok
In the Pad_Designer window, select File > Script...
In the Scripting window, click Browse...
In the file browser window, change File of Type to to All Files (*.*).
Select a PSR file, then click Open.
In the Scripting window, click Replay.
In the Select Library Padstack window, click Ok.
Import package

In Allegro, select File > Script...
In the Scripting window, click Browse...
Select the SCR file you downloaded, then click Open.
In the Scripting window, click Replay.