This mods adds several tiers of spider vehicles, prior to the vanilla spidertron.
Pentatron: small red-green-grey tier vehicle with 5 legs, twin shotguns, and a 4x4 grid.
Crabotron: 4 legged, red-green-grey tier, flamethrower weapon, heavier armor, 6x4 grid.
Insectitron: 6 legged, red-green-grey-blue tier, Twin chainguns, 6x5 grid.

Each one also has a fusion variant, that uses the personal fusion reactor in the recipe to remove the fuel usage, as well as improve the grid size to 6x5, 7x6 and 8x6 respectivly. They're red-green-grey-blue-yellow tier.

This needs to be done on the "grid" side (thus power armor, vehicle, tank, train, etc, whatever creates the grid).
So you should send your request to the mod providing the vehicles.
Their Prototype/Grid::equipment_categories should include at least one of the following tags (can be multiple):
"vehicle" : Equipment usable on any vehicles, e.g., rocket pod.
"tank": Equipment usable on any tank, e.g., gun pod.
"tank-M": Equipment usable on medium tank or above, e.g., minigun pod, autocannon pod.
"tank-H": Equipment usable on heavy tank or above, e.g., cannon pod.

As a reference, the vanilla Spidertron is defined equivalent to Medium Tank (MK2) of my tank series. So it would have tags {"armor", "vehicle", "tank", "tank-M"}
I am not sure how such mod define these modded spider vehicles. From your description, they are just using different weapons but does not look significantly different from vanilla.

BTW, I have made my own mod Schall Arachnid Platoon for the extra Spidertrons. Maybe you may give it a try.

actually, I talked withe the maker of the the insectoron mod , they will add support on their own end.

One thing about your tank and spider mods, they have a LOT of tiers, things are getting a little bloated.

With just vanilla, the three tiers of tanks (or spiders) are just corresponding to the three tiers of modular (power) armor. Jumping from modular armor to power armor MK2 is too large the gap. So I do not see any reason to provide just basic tier and then directly MK2.
(Plus there are options in the mod to disable MK1 & MK2 series, so only having the basic tier tanks. So this should not be a source of problem.)

If you are instead complaining the different classes... Well, they ARE different weapon choices. So honestly I do not understand how to provide more weapon choices without more classes...

The problem is that in Factorio, vehicles are of limited utility. You can't remotely control them in vanilla like in an RTS (except spider vehicles, but they don't have any pathfinding and can only order one per click.)
Power armors as well, they mostly have no use beyond being a stepping stone for the next tier, but there's less of them. And with vanilla enemy power levels, there's little need for so many vehicle tiers... I think having an option to limit it to a single upgrade would fulfill what I want.

Although, this is my opinion, not fact. This is your mod, you do with it as you wish.