I don't think it's weird at all. All you really have to do is link them through some motivating factor; at this point why is it necessary to put the cards away and show something else? Find an effect which you can patter up to connect to the previous card effect and use it as "another example of the same principle". Then find some reason to go back to the cards.
Really since the audience doesn't have a program to know that you're going to do a card effect, another effect, then more cards they're not going to think "hey, why not put the card tricks together?". By the second card trick they will likely not be thinking of the previous one unless you give them reason to.
Another option is to find a reason to necessitate a new deck. Maybe you want to use a new sealed deck every time to prove it's above board. Maybe you move from playing cards to a Zenner deck. Maybe the cards are for some reason scattered all over the floor, have been mangled, or are for some other reason inaccessible - obviously a new deck is in order. Did the previous trick include a signature, or several - time for a fresh deck and a full 52 possibilities.
P.S. I can't remember the thread or even exactly which forum it was but the videos at the Mind Science Foundation revolved around magic for one of their conferences. Teller touches on what I'm trying to express here on the first video on the page. It's his second point when he's dealing with the sponge balls and the position of the table:
http://www.mindscience.org/magicsymposium/