No there are not merely differences in terminology. There is a big chasm between key doctrines. There is a significant difference between Total Depravity and Partial Depravity. There is an important difference between Unconditional Election and Conditional Election to name just a few. One can't just try to smooth over the vast and contradictory views of both parties as if nothing of substance mattered between their opposite teachings.
Personally, I don't find it contradictory, at all.
Both 'camps' believe and teach 'Perseverance' which is of course not defined except to say that the saints 'persevere', you see, and both Calvinism and Arminianism, as systems, demand the 'right' to decide for themselves whether or not someone is 'saved' depending on whether or not some, again undefined 'standard' of someone's 'Lordship' is met by another, as seen in their 'works'. Both systems seek to bring in "works" as the final determining point, albeit it is somewhat easier to discern with Arminianism.
Both systems are seem to embrace what is known as "Lordship Salvation" and both are in opposition to what is inaccurately known as "free grace" teachings.
Some of the 'code words' and 'straw man' phrases include (and I've seen them several times on the BB, BTW) "we don't believe in any 'easy-believism' " (I guess they believe in some 'hard-believism' whatever that may mean.); "really (or truly or genuinely) saved" (or even worse, "really and truly saved") (Uh - where does Scripture ever speak of "falsely saved"?); or its double first cousin "really and truly believe" (Correct me if I'm wrong, here, but I believe Scripture only speaks of two categories, in this - "believe" and "believe not" in Jacobean English. I simply find no Scripture to suggest one can "partly believe", but admit I could have missed it, so help me out, here, if I am in error, on this.); "'head' belief"; "heart belief"; "fire insurance"; and on and on the "canonized rhetoric" goes.
If this alleged standard is not met, for the Calvinist, obviously the individual is not and has never been saved in the first place, because they obviously "don't have it" because they never really had it. At least the Arminian gives two alternatives here- either they "had it" and lost it, or they never really had it in the first place, because now, at least, they "don't have it".
What is the objective difference between "
don't have it" and "
don't have it" pray tell?
I admit, I have a very difficult time telling the difference, here, between these two end points.
Ed