In which case the question is: why are you doing a stupid thing
I agree, without any sort of visual hierarchy in the text it all becomes very homogeneous and difficult to read. Doing something a bit more like Hatch Prints, which are text heavy posters but work because of their use of variety:
Also, considering the time period TF2 takes place in, that poster makes even less sense with its choice of fonts as well as design tropes that primarily originated with the advent of computer-aided design. TF2's designs for posters generally look a bit more like they're from the 1950s or 60s (despite the game taking place in the early 70s) but that makes sense in a way considering the visual design of TF2 in general is based on Leyendecker, who was active primarily in the late 40s and 50s.
So, I'd say it's best to base your design on that time period. As such, here's some coffee advertisement examples from the time:
^^^ (keep in mind, this is a Magazine ad, so the body copy text would not be usual for a poster)
I can't find too many good examples of text-heavy posters from the time, but I'd say just take what you can see above and use your best judgement. :]