Since you're trying to follow canon as close as possible, I should point out that the Tantive IV was not captured by the Executor - it doesn't appear until Episode 5. You'll remember that it was just a regular Star Destroyer that appeared at the start of Episode 4.
"There is no such thing as coincidence, only inevitability" - xxxHoLiC
"Justice? But I don't serve justice, Watson, I serve the truth." - Sherlock Holmes