you got your top 2 right. thomas or howard. i dont keep a TE, especially a TE whos QB may not even start the first couple games. here is what i would do to choose between them. look at the other teams, and figure out who you would keep from their teams. that should give you a good idea of the pool of players. next, would be to know what pick you have. some leagues will tell you early because its based off of finish in league championship, some do random every year.if you know the order everyone will pick in, find your spot, and figure out who will take what ahead of you. this is where understanding your league mates comes in hand. if you pick at 8, and the 7 guys before you need WR and there are a bunch of good ones out there to take, keep a WR and draft the highest RB on your board. same for vise versa. this gives you the best chance to get a good return on who ever you let go.
otherwise if you dont want to do all that work, just take howard. it shores up your running game giving you 2 top 12 potential RBs, and its easier to fill the WR spot than it is the RB. case and point, you yourself are giving up Juju and robinson. both guys who can be WR1. along with will fuller and goodwin, both guys who can be mid to high WR2s.
now here comes the fun part, because i think ajayi might rival howard for that spot on your team. ajayi’s stats this year were not impressive, but that was changing teams mid season, and sharing the backfield. with blount gone (if he IS gone which i expect him to be) ajayi takes over that first and second down spot. he was already ramping up toward the end of the season, getting more and more touches every single game. along with continuing this trend into the playoffs. wentz doesnt play the first 4 games? no problem. he produced just fine without him, even in the playoffs agaisnt the vikings. there is a case to be made here. but that case needs more information. so, if you have to decide soon, its howard over ajayi. if you can wait till your draft or around that time, then keep ajayi in mind i would say.
anyway, sorry for the novel. i can ramble on for hours if you let me haha.