@MasterMark26 Glad I could share the ideas !
For the trucks, I 3D-printed some models on Shapeways and added them to my collection after painting them. Here is the link to the model in my shop :
https://www.shapeways.com/product/RK9QJAH6V/wwi-truck-x12?optionId=128058468&li=shop-inventory
You can see the end result on the Plastic Commando’s YT channel once he painted them (and he did a great job) : https://www.youtube.com/watch?v=ADQnU6f0gKQ
There’s other options like gun-mounted trucks, which could be a hybrid mobile-artillery / AA battery, armored cars, and more ! So if you want to make things more interesting, feel free to be creative !
For your tank idea, I wonder if the increased cost would make them appealing. They sure would boost your offensive power by boosting your infantry, it’s just a question of would you be able to buy enough to make a difference. Let me know how it turns out !
Happy gaming, good sir !