That's a convenient combination!
Keep in mind that both of these effects can be a little underwhelming on their own merit.
I would either make sure I would be able to find both, or substitute them with something else.
For tutoring purposes:
Caltrops can be found by
Trophy Mage! (just like other convenient items in your list like
Rings of Brighthearth,
Chromatic Lantern and
The Peregrine Dynamo). I would
consider that inclusion.
As food for thought I'd like to share my experience that it's a lot more fun to be proactive than to build yourself a pillowfort.
I like to pressure my opponents with a bit of board presence, even if it's just a bunch of 2/2s.
If you look for options that replace themselves upon casting (ETB: get a card - like
Trophy Mage /
Knight of the White Orchid, or ETB: remove target .. - like
Skyclave Apparition or something), or alternatively double up on defence with
Vigilance or something.
Actually, looking at your list, you're not ramping a great deal.
Knight of the White Orchid, Loyal War Hound,
Space Marine Scout and
Scouting Hawk will all be likely to contribute to your board while progressing your long-term
game plan.
In my view, sitting behind a board of permanents usually contributes to a more enjoyable kitchen table experience.
I'm aware this may not be true for you, so feel free to disregard this view.