This article is completely misrepresenting CCG OLs. It's not the price that's stopping you from spamming them but rather build time. CCG is a much faster paced game that simply doesn't give you the freedom to wait and build up an OL army, especially in multiplayer.
"Add extra weaponry for more firepower", what? Gatt upgrade is there to counter the biggest weakness OL has - infantry. An uncompanied/unupgraded OL will just keel over once it meets rocket infantry; gatt upg is there to prevent an OL from needing a permanent entourage that covers it from infantry. In terms of "extra firepower", it really doesn't add any damage where it matters. A ZK equivalent would be Lightning Rifle vs Beam Laser against a fleet of Fleas.
Prop towers turns an OL into a moving healing field, and is such a braindead pick that 99.9% of the time your first OL will upgrade a prop tower. Prop tower benefits the entirety of your army, whereas gatt only benefits the OL itself. Having multiple OLs means a mix of prop/gatt upgrades.
As for the bunker upg, we don't really talk about it. It's a complete noob trap and lacks even a situational use.
"Adjusting to the battlefield" is practically never a reason behind picking a specific OL upgrade. First OL gets a prop, second OL gets a gatt if/when you can afford it. How the game is going doesn't affect this at all.