Gaza has resistance groups with small arms, while Israel has reduced Gaza to a smoking ruin with 2000lb bombs dropped from F35's, driven over countless Palestinians (dead and alive) with Merkava tanks, sniped countless children with drones, and dropped white phosphorous on civilians and UN Peace keepers. Israel has access to a devastating array of weaponry, and has no qualms about using any of it for anything.
Many rockets fall within the SALW category.
And when compared to F35s, tanks, missiles and the iron dome... I think simple, often homemade, rockets are small arms.
No conspiracy is needed: we have several statements from IDF members about the Hannibal Directive being used, and about the types and quantities of munitions being used; we know the IDF destroyed hundreds of vehicles.
Of course, if you define "credible sources" as the western main stream media, nobody will put it all together like this.
https://electronicintifada.net/content/how-israel-killed-hun...
https://www.thejc.com/news/met-police-reportedly-raid-home-a...