AFAICT, as of commit a0a422c,  we have 2 different logics to evict outbound peers : lagging-chain (`ConsiderEviction`) and (`CheckForStaleTipAndEvictPeers`). The former to sanitize out lazy/buggy peers who have never sent us a valid header and are always staying behind our tip, the latter triggered in case of stale tip due to block variance to seek a better chain by rotating our outbound peers if we already reach an outbound limit (`EvictExtraOutboundPeers`).

Block-relay-only peers were introduced by #15719. Contrary to outbound full-relay peers who provided us at least a useful header, they're not protected by lagging-chain eviction.

We actually have a comment inside `ProcessHeadersMessage` indicating the contrary behavior. We should either document cleanly that block-relay-only aren't protected or effectively extend the scope of protection to them.

Hinted during #19724 review, see https://github.com/bitcoin/bitcoin/pull/19724#discussion_r475144532
{
        /* As std::make_heap produces a max-heap, we want the entries with the
         * fewest ancestors/highest fee to sort later. */
        return mp->CompareDepthAndScore(*b, *a, m_wtxid_relay);
    }
};
}
bool PeerManager::SendMessages(CNode* pto)
{
    const Consensus::Params& consensusParams = m_chainparams.GetConsensus();
    
    
    if (MaybeDiscourageAndDisconnect(*pto)) return true;
    
    if (!pto->fSuccessfullyConnected || pto->fDisconnect)
        return true;
    
    const CNetMsgMaker msgMaker(pto->GetCommonVersion());
    
    
    
    bool pingSend = false;
    if (pto->fPingQueued) {
        
        pingSend = true;
    }
    if (pto->nPingNonceSent == 0 && pto->m_ping_start.load() + PING_INTERVAL < GetTime<std::chrono::microseconds>()) {