This is literally the intended design and has not been an issue for years now. Ostheer has seen many metas and many with Gren builds.
It was working many year ago but it does not work anymore and that is why grenadier are problematic although they have been buffed. If you want to debate Grenadiers this is not best thread and we can do it another.
Also Osttruppen work as intended, they just appear to be a bit too strong in the current meta.
Ostt are strong but that does not mean that they ostheer faction should become the only faction that has to invest in tech to have access to their doctrinal CP 0 infatry, especially since there are other option available.