Low opted to name just two out and out strikers for this summer's tournament in Brazil, with Miroslav Klose and Kevin Volland expected to shoulder the goalscoring burden.
Lukas Podolski could also operate in a central berth, but Thon believes Low's decision could prove costly and says he should have taken another of the Bundesliga's striking stars.
The former Germany international told Goal: "We could be better positioned. One has to ask why he has not taken Max Kruse? For me there is no clear statement.
"We have left ourselves thin. Only Miroslave Klose and Kevin Volland are strikers. Steffan Kiessling or the stronger Lasogga could have gone.
"He has almost single-handedly kept Hamburg in the league. Every national team needs a war machine like him in a tournament."
Germany face a tough task to emerge from Group G after they were pitted alongside Portugal, Ghana and the USA.