The phrase "arguably then" is correct and usable in written English.
It is often used to introduce an opinion that is regarded as controversial. For example, "Arguably then, climate change is the most pressing issue of our time."
Arguably, then, the Court intended its decision to apply to all types of testimony as well.
Arguably, then, we might get a real debate on the issue with greater public engagement and participation.
Arguably, then, Australia's environmental laws and approvals processes need a rapid reboot to include the "most important" environmental issue there is.
A hundred years ago, Jack London - arguably then America's most prolific and successful author, with an income from writing equivalent to today's biggest Hollywood actors - was awaiting the imminent publication of his latest (and greatest) work, The Iron Heel.
Arguably, then, there was no such thing as a weed until mankind developed the need to discriminate, which came with the development of agriculture in the Neolithic era, around 9,000 B.C.
Arguably, then, Brazil is now the world leader in tackling climate change.But how did it break the vicious cycle in which it was widely expected farmers and cattle ranchers (the main culprits in the Amazon) would make so much money from clearing the forest that they would go on cutting down trees until there were none left?
If cloning for stem cell research violates the respect the embryo is due, then, arguably, so do in vitro fertilization procedures that create and discard excess embryos.
Arguably, she then undermines these efforts by thanking both John Galliano and Leni Riefenstahl in the film's credits.
First, they are a deeply embedded part of the higher education system, existing in some form since at least 1962 (and arguably before then).
It is arguably SMEs, then, that stand to benefit most from growth in emerging Europe and get first-mover advantage that multinationals are not nimble enough to exploit.
Surely once we equalised (arguably before then would have been better) they needed to throw the kitchen sink at us and go for a winner?
