First, read
this again.
Second, since we
are playing Imperial Guard, we always need to consider the basic Infantry Squad; 50 Points
Grenade Launcher and Heavy Bolter; 65 Points - Anti-Infantry
Plasmagun and Autocannon; 75 Points - 'All Comers'
Plasmagun and Lascannon; 85 Points - Anti-Tank
However, what sets Infantry Squads apart from vehicles is the ability to receive Orders, as well as being a Troops choice. Then, in Annhilation games (or, whenever you want) you have the option for
Combining Squads to deny your opponent Kill Points, and/or to enable maximum efficiency of your Orders.
Any time you want to take a Tank, look at it's Point Cost, and decide how many like Infantry Squads you could get for the same price.
Lastly, Vehicle Squadrons; Read up on page 64 of your Rulebook.
All Crew Stunned results count as Crew Shaken. Essentially, vehicles in Squadrons get free Extra Armour. However, all Immobilised results count as Destroyed (Wrecked), meaning your opponent can now destroy your vehicles with Glancing Hits.
As vehicle squadrons, all vehicles must fire at the same target. As tanks, this
will lead to massive overkill. Or, inefficiency of fire. You want to spread your Pie Plates over as many units as possible, don't you? Or, at least you might want the choice to.
Also, Hits are taken against the Squadron. And you have to allocate hits
before you roll on the damage table. Instead of 3 Hits on one vehicle, you're taking 1-2 Hits each. This can end well, or catastrophically bad.
Not to mention that sometimes it's
really hard to get tanks to fit on the table with coherency of 4".
When you start to combine these things, you realise that you should probably never take vehicles in Squadrons if you have Force Organisation slots to spare. Spread out your tanks. You don't really lose anything by doing so. But, you gain individual effectiveness. Of course, this may backfire in Annihilation. But, at the same time, you've got multiple tanks. It rarely goes wrong.