Not my first choices but they are both pretty good WRs so I would definitely be okay with them.
for me its a case of not being sure there's a big name free agent wr id be fully comfortable with coming in here and being a big time receiver worth the money we give them - whereas i think we can add 2 solid lower cost free agent receivers who are really high level number 3 receivers (maybe even number 2 receivers) maybe you resign wallace and cut maclin and add a young rookie and suddenly you've transformed your wide receiver corps - you might not have a definite number 1 receiver straight off the bat but you'll have vets in the building if the rookie needs some acclimation time, you'll have a wr group with complementary skillsets and you'll have legitimate depth with guys like camp, moore and perriman duking it out just to grab the last 2 spots on the depth chart (camp and moore likely win because of special teams)
so i think moncrief + gabriel + wallace will likely cost lest in yearly average than one of the top free agent wrs + maclin in terms of cap space and they is likely less competition for them too (it's how we got woodhead on a decent contract so quickly with little competition because we found a guy we liked who wouldnt attract the first round of interest and gave them an offer with some guaranteed money and woodhead said yes very quickly)
then add a day 2 receiver in the draft (or day 1 depending on who's there)... (pick your poison on this one depending on who you're into) but for the sake of argument ill say anthony miller...
your revamped wr corps looks like this:
Wallace, Moncrief, Gabriel, Miller, Moore, Campanaro
now that's not the flashiest group but its a group with complementary skillsets that doesnt require rushing the rookie into the starting lineup but also doesnt hinder his development if he performs well - you've got deep speed, a big body on the outside, a shifty slot receiver with a knack for finding space in the middle of the field, a promising rookie who's physical and a smooth route runner who has an enormous chip on his shoulder - then you add chris moore who's looked to be improving steadily while also being a good special teamer and camp who when healthy has always been a useful part of the team even when not targeted and has been the leader in the clubhouse for punt returning for a few years now (this is as long as we re-sign camp which isnt a given but id imagine he has nowhere else to go that will offer him a better contract than we will)
i personally like the look of that receiving corps especially when you add the fact that it doesnt even include woodhead yet or any tight ends we find from somewhere too...
i realise its not the flashy outcome that many on this forum would want but id personally be elated with this outcome especially as it doesnt mortgage future cap space
and let's be honest literally any improvement at wideout from last year will vastly improve the offence if joe continues to improve (here's hoping james urban really does help flacco get back in rhythm)