In the first sentence the state of not being fluent pervades time (that is from some not too remote date in the past), is to be extended into the near future. However, in the second sentence, the state of not being fluent is not considered beyond a certain point in the past, which is nevertheless very near in the past since "now" makes it a point of the recent past: what the speaker is saying is that at that particular point of the past he/she is thinking about the state of not being fluent was true; (note that "now" does not specify the same period of time that the use of "now" in the first sentence points to); we infer from that that this situation probably perdures but this is speculation that only the context could justify (in the present case there is no doubt). There is then no great difference in the reality conferred to the reader/listener in this case because the verb is a state verb, the state in question can't but remain true in the present and the near future and because the point in the past is very near.
A tangible difference exists when the verb is an action verb.
If he had trained he would answer us properly, now.
The action has started some time in the past and goes on, he keeps on answering poorly and there is no indication that this has stopped, it goes on.
If he had trained he would have answered us properly, now.
The action has started some time in the past and went on but stopped in the past (past perfect) or, as well, the action could be considered as having taken place at a point of the past (pointwise action); in any case it had an end in the past.